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CHEMICAL NEWS .222 Explosions in Flour-Mills and Coal-Mines.

May 23, 1879. aspirated through at a speed of 15 cubic feet per twenty- present in chamber exits, but add peroxide of hydrogen to four houis has shown an excess of peroxide at the finish the solution and all difficulty vanishes, the sulphurous of the experiment, even when caustic soda was presentacid is oxidised to sulphuric, which acid is easily titrated. in excess also. I have evaporated a 10-volume solution I will now proceed to give examples of its use in of peroxide to half its bulk without driving off more than various methods of analysis. Some samples of soda.ash two-thirds of its active oxygen, but when reduced to that contain so much sulphite of soda that it is impossible to bulk caustic soda was added, the elimination of oxygen estimate the amount of alkali accurately by means of was so violent as to amount almost to explosion. When standard acid. As an example of this kind of ash I give kept in solution in the laboratory a 10-volume solution of the following analysis of a sample of ash made from caustic peroxide is moderately stable. During 1878 the following salts, which contained by the acid test in the ordinary tests were made of a sample by the bichromate method way 30 per cent of alkali without peroxide of hydrogen, over mercury :

whilst the addition of a few c.c. brought down the axual

percentage to 21. The escaping carbonic acid carries August 2

90

away a great deal of sulphurous acid, but it does not do 9

this if peroxide of hydrogen is present. 24

8.0 September 1

Sodium sulphide

o'o98 79

sulphite

22-982 24

sulphate

20207 chloride

33'048 A few drops of ether were now added to 250 c.c. of that

silicate ..

I'214 sample of October 24, and the following tests continued :

carbonate
November 7
7'2
hydrate..

12.800 72

8.747 December i

24 Ether seems to preserve it, a fact which has been black-ash ; a few c.c. added to the liquor under examina

Peroxide of hydrogen is very useful in the analysis of known for some time. This was also mentioned to me by Dr. Messel, of Silvertown, in August, 1878, a method tion gives at once the total alkali, which number needs no I have used ever since. It is stated in all our text-books correction for sulphides, hyposulphites, &c. that peroxide of hydrogen is neutral to test-papers. Now, tions, such as the oxidation of iron salts, colouring

This reagent is very useful for many laboratory oxida. all commercial peroxide is faintly acid with the excess of hydrofluoric or hydrofluosilicic which is added and which matters, experiments on bleachings, &c., &c. In fact the should be estimated in each sample before using it.

applications of this useful substance are legion. I first I have used peroxide of hydrogen since 1873, and 1873 ; but its application then was very limited as I had

commenced to use this reagent for testing vitriol exits in latterly in comparatively large quantities, and I have made it a rule to examine each purchase as follows :

to make my own, and a perfeâly pure peroxide of barium

is not 100 C.C. of the peroxide was evaporated to dryness with peroxide of hydrogen was looked upon as a sort of rara

a very easy thing to make. In those days 10 c.c. N soda, ignited, and taken up again with water. avis, to be found only in the laboratories of schools of N acid was then added to neutrality, chromate of potash, chemistry, and its use was not much extended until a

N and finally titrated with nitrate of silver. The results pure peroxide of hydrogen entered the market as a com.

mercial article, to be bought and sold in the same way as of many experiments upon this one sample showed that other reagents. 100 c.c. of peroxide neutralised 0:2 c.c. of N soda and

Heaton Chapel, May 12, 1879. N consumed 3-4 c.c. of nitrate of silver. On the evaporation to dryness of the peroxide by itself a very pungent acid is liberated, and which can be easily told is not

EXPLOSIONS IN FLOUR-MILLS AND COALhydrochloric. In order to show the moderate stability of

MINES. peroxide of hydrogen, I have lately had a sample sent

By WATSON SMITH, F.C.S., F.I.C. me of commercial peroxide which was at least fifteen months old. When treated with bichromate over mercury it gave 7 volumes of oxygen, and I know that no special I believe it was about the year 1871 that the great explo. care, or indeed care of any kind, was bestowed upon the sion took place at the Tradeston Flour Mills, near Glasgow, sample.

but not having any particulars with me here, I cannot Having, then, a ready method of testing its contained speak with absolute certainty as to exact date. As this amount of active material, it remains only for me to show was a catastrophe atterded with loss of life and great that peroxide of hydrogen is an exceedingly useful damage to property, a searching investigation was made oxidising agent, for it oxidises by reason of its loosely into its causes. Several theories were propounded, but combined oxygen, and when an excess is added to any none appeared to be satisfactory or to meet the circumsubstance or to any solution, that excess is readily stances but the one which I was enabled to give. This eliminated, leaving only as a residue that most neutral explanation was suggested to me on reading a short note substance water.

in Dingler's Polytechnisches Fournal, of which an abstract There are many substances often seen in the laboratories appeared under the head of " Technical Chemistry” in of alkali works that cannot be readily and accurately the Journal of the Chemical Society. The author, who examined except by its use ; such as the total alkali and wrote from Austro-Hungary I believe, had noticed how crude soda liquors' or in black-ash, and certain qualities artificial lightning was made in theatres by blowing lyco. of soda-ash which contain sulphides or sulphites.' In the podium seed through a flame, and he found that dry flour testing of chamber exits it is extremely useful, inasmuch would also do for the purpose. Then he argued that flour. as sulphurous acid is not an acid easily titrated, for the dust in quantity might also be caused to flash off, given a normal sulphite of an alkali is not neutral to test-paper, due admixture of air and the introduction of a spark or and therefore on titrating a sulphite with a standard acid flame. In this way he sought to account for sundry explo: the point of neutrality is not clearly defined and distinct. sions in flour-mills in his part of the world. The sparks This want of clearness in the ending has been stated by might be struck by the stones coming into slight collision, some chemists to be due to the carbonic and nitrous acids' or incautious approach with a naked flame might fire the

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On Nitrification. May 23, 1879.

223 mixed atmosphere of the stive-room in a Alnur-mill. The otherwise slight coal-mine explosions may be expanded into explanation I gave, which appeared in the Glasgow Herald, great disasters, owing to the clouds of coal.dust raised into was based on this, and, so far as I know, I think I may and diffused through the atmosphere of the workings; such claim priority as to the bringing forward of this view, as far an atmosphere, especially in presence of traces of fireas either Great Britair. or America are concerned ; at least damp, being thus suddenly converted into an explosive I understood the Scottish Royal Society's Commission of mixture. This view, too, explains the frequently observed Inquiry on the subject gave me at the time the credit of fact that an explosion in a coal-mine often sweeps over it." The drift of my explanation was the following:- very considerable tracts of the workings. I am told that “ If the grinding-stones be supposed to get slightly out of Prof. Marreco, of Newcastle, has investigated and expegear at any time, as they quite possibly may, they may rimented on this subject. come in contact with each other so as to strike sparks It has occurred to me that in view of these similar causes amongst the fine four-dust suspended cloud-like in the of, and liability to, explosions, both in flour-mills and in atmosphere immediately in the neighbourhood of the coal-mines, the electric lamp would be the best and safest

Such an attenuated combustible mixture as flour means of illumination that could be emploved. Such a just suspended in air approaches the condition of a mixed light could be confined in a glass globe, hermetically gas, and, the proportions being favourable, an explosive sealed, and would be a fixture of course. Means of sig. mixture. The whole atmosphere of the stive-room is often nalling could also be adjusted in coal-mines. Thus most laden with this dust. Now, imagine a single grain of four- stringent and rigorous measures would be rendered feasible dust inflamed by contact with a spark from the stones, or to prevent the introduction of matches, lights, or lamps and by a naked flame brought into the room, what is to hinder lanterns of any kind into the workings. At the present this inflammation from passing instantly, and like a flash, cost of the electric lamp it might also with advantage be from grain to grain, the atmospheric oxygen supplying a used in the stive-room of four-mills, and others where common means of combustion ? quite analogously to the clouds of four-dust may be raised at any time. This recase of an explosive gaseous mixture. Carbonic acid and commendation may of course have been already made; if steam are thus generated suddenly, and at an elevated so I have not observed it, and on this ground may plead temperature, and the sudden expansion in a closed space, excuse for failing to acknowledge prior claims. like the interior of a mill, produces the pressure resulting Zürich, May 9, 1879. in disastrous explosive effects."

Berthelot has calculated that the sudden increase of volume which may take place is amply sufficient to account for explosions. Under certain normal condition, in which great rapidity in the revolution of the stones is attained,

PROCEEDINGS OF SOCIETIES. and the grain is unusually dry, one can even, with Mr. L. Smith, conceive that sufficient heat may be developed to

CHEMICAL SOCIETY, cause ignition, especially if some hard foreign body-such as a piece of wood, for instance—by any accident should get

Thursday, May 15, 1879. in with the grain in grinding. Its attrition and pulverisation might, perhaps, cause ignition of the dust produced. Still,

Dr. WARREN De la Rue, President, in the Chair. an abnormal rapidity of revolution would also, in case of slight collisions of the stones, cause showers of sparks to fly, or an ordinary lantern or bare flame might be brought The minutes of the previous meeting were read and coninto the room, and these would be quite sufficient to in. firmed. The following certificates were read for the first flame the atmosphere, given favourable proportions of time :-C. J. Wilson, G. S. V. Wills, W. H. Kerr, G. R. four-dust and air existent at the time. This it seems to Tweedie. me is an explanation nearer at hand, and also more pro- The PRESIDENT then called on Mr. WARINGTON to read bable than the other.

a paper "On Nitrification (Part II.).” A. Müller was the Mr. Langbeck in his paper (CHEMICAL News, vol. xxxix., | first to advance the opinion (Chem. Soc. Journ., 1873, p. 191), though thinking himself justified “in opposing | 1267) that nitrification is due to the action of a ferment. these explanations and substituting another one,” neither, Schlæsing and Müntz proved this to be the case (see in point of fact, does practically oppose them, nor does he Part I. of the author's paper), and from recent experiments offer anything in substitution but an unlikely surmise--a show that soils which induce nitrification have this power mere “ smell of impure hydrogen," on which opinions destroyed by exposure for one hour to 100° C., and that again might differ. This surmise he tries to support by ordinary moulds and mycoderms injure rather than proexperiments, which, however, on the whole, go more to mote nitrification. The author also mentioned that the second the explanations already given above than his own. above experimenters were at present engaged in an attempt The experiment with the coal-gas, as recorded, is abortive to isolate and cultivate the organism, which promised to prove anything on the subject; and, finally, his opposi- good results. The objects of the author were to ascertain tion to the explanation given, and his substitution of the influence of light, temperature, variations in the another one is a complete fiasco, for he winds up asking composition, and concentration of the solutions on the the way to the source of his own surmise. Having process of nitrification, the rate at which it progresses, and attained this, but failing to find his way out of it again, he the relation of the nitric acid produced to the ammonia puts it to the reader to find the way out for him in a consumed. In nearly every case exposure to light precouple of questions further. And this is opposing an ex. vents nitrification, and in all cases the exposure hindered planation and finding a substitute! To both questions I the process to a marked extent. The mould which devefor one would reply “Certainly, No! as far as the case lops in a solution containing tartrates is incapable of effect. in point is concerned.” If one of them were admissible ting nitrification. The presence of carbonate of calcium it might surely be expected that explosions should occa. seems to be indispensable to the growth of the ferment. sionally be heard of in our bakers' ovens. Perhaps Mr. The author pointed out the significance of this fact as Langbeck is not aware that a well authenticated explosion explaining the absence of nitrites and nitrates in soft is on record caused by the falling of the contents of a peaty waters, and as bearing on the utility of applying flour-sack. The cloud of flour.dust came in contact with lime, &c., to reaty soils rich in nitrogen, in a form una gas-flame, and a very considerable explosion occurred. favourable for absorption by plants. A very small amount The Fournal of the Chemical Society of London for this of organic carbon is requisite. An extensive series of month contains a brief account of Berthelot's views on quantitative experiments is given as to the effect of tem. the subject.

perature. The upper limit of temperature at which nitri. It is is now a pretty well ascertained fact that some fication takes place has not been determined. 40° C. is,

0'02 trace

224
Alkaloids of the Aconites.

{ ,

May 23, 1879. however, fatal to the process, which can proceed at 10°, chiefly of veratralbine, C28H43NOg. A small quantity of and probably at still lower temperatures. In all cases another base is present, yielding veratric acid on saponithere is a period after the addition of the ferment during fication. The mixture of veratralbine and this base is which no appreciable effect is produced. This period the powerfully sternutatory, but this property is lost by boiling author terms the period of incubation. This period is with alcoholic potash. Hence it is probable that the considerably shortened by increasing the temperature. sternutatory constituent is veratrine (Couerbe). Neither Thus, in a solution containing 640 milligrms. AmCl per jervine, pseudo-jervine, rubi-jervire, nor veratralbine excite litre the period was at 10° 78 days; at 30°, 19 days. As sneezing. Verátralbine gives with sulphuric acid a red the solutions become stronger the period increases. Thus, colouration resembling that given by cevadin and veraa solution containing 80 milligrms. the period was only trine. No evidence of saponification or other decomposi31 days at 10°, or 12 at 30°, instead of as above 78o and tions was obtained on boiling these bases with alcoholic 19°. The presence of bacteria does not promote nitrifica- potash, the minute quantity of supposed veratrine ex. tion. The author discusses the interesting question why cepted. in some cases nitrites, and in others nitrates, are produced. Dr. Wright then read a paper " On the Alkaloids of When the ammonia disappears before the nitrous acid is the Veratrums (Part IV.)." "Alkaloids of Veratrum converted into nitric acid, the nitrites left in solution are viride:--On treating about 18 kilos. of dried roots prevery stable : if, however, the oxidation of nitrites sets in cisely as described in the foregoing paper, the first treatbefore the ammonia has been consumed nitrates are ment with ether left undissolved some pseudo-jervine, formed with great rapidity. In no case is the whole of the tartrates obtained from the ethereal solution yielded the ammonia obtained as nitric acid. Some experiments no veratralbine, but jervine crystallised out from the second were made as to the part played by the heating effect of ethereal solution on standing. Traces of rubijervine were the sun's rays in preventing nitrification, as a temperature observed. The ethereal mother-liquors dried up to a of 40° proved to be fatal. It was found that a solution powerfully sternutatory amorphous mass, closely resemsheltered partially from the heat, by a screen of alum solu- bling the “ veratralbine” similarly obtained from V. album tion, but fully exposed to the light, of the sun, nitrified roots. It gave on analysis, however, C32H49NO,, the forsooner than a similar solution exposed to the heat and mula of cevadin, and on saponification it yielded about the light. In both cases nitrites were formed which were very theoretical quantity of cevadic acid with a trace of veratric permanent. The paper concludes with some interesting acid. The following table represents the approximate experiments on the conversion of nitrites into nitrates by yield of the different bases from the two roots per kilo.:the ferment. This change apparently takes place only in

V. album. the dark, and a ferment which is quite competent to convert

V. viride. ammonia salts into nitrites is apparently not necessarily

Jervine

I'30

O'20 competent to convert the nitrites into nitrates. Some Pseudojervine

0-40

0'15 solutions, however, which are nitrifying seem to possess

Rubijervine

0'25 this power in a high degree. The progress of nitrification

Veratralbine

220 is not uniform; it begins slowly, increases in rapidity, and

Veratrine ..

9'05

less than 0.004 after reaching a maximum again diminishes. The strongest

Cevadine
apparently absent

0:43 solutions nitrified by the author contained 180 parts of nitrogen per million.

4'20

0.80 The President said the author had investigated the The jervine and pseudo-jervine from V. viride agreed in subject with great acumen. It was interesting to observe melting point, properties, analytical numbers, &c., with that the process might produce either nitrites or nitrates. the specimens obtained from V. Album.

Dr. Wright then read a paper “On the Alkaloids of the Veratrum Family (Part 111.),” by C. R. A. Wright of the Aconites (Part IV.),” by C. Ř. A. Wright and A.

Dr. Wright then read a third paper" On the Alkaloids and A. P. LUFF. Alkaloids of Veratrum album.-- The P. Luff. Japanese aconite roots.—The authors have ex. authors have examined the alkaloids extracted from 12 amined two different batches of roots, treating them with kilus. of dried roots hy percolating with alcohol acidified alcohol acidulated with tartaric acid, evaporating, adding by tartaric acid (I part per 200 of rorts), evaporating to a small bulk, addition of water, filtration from resin, and water, making alkaline with sodium carbonate, and then treating with a slight excess of caustic soda and ether. shaking with ether. Repeated treatments with

ether failed

to dissolve all the alkaloid present, some being obstinately After repeated washing with ether an insoluble precipitate retained by the alkaline fluid; this appeared to be was left, which seemed to consist principally of a base crystalline. The ethereal extract, after purification by hitherto undescribed, which the authors name pseudo- shaking with aqueous tartaric acid and treatment of the jervine, C29H43NO.g. It is snow-white, and melts at 299'; crude tartrate solution with soda and fresh ether, gave by crystallising anhydrous from alcohol; with sulphuric acid it gives a yellow solution, gradually turning green. The spontaneous evaporation crops of crystals. These crops

were fractionated and re-crystallised; all gave numbers ethereal solution contains, besides small quantities of indicating the formula C66H88N2021. Treatment with hot pseudo-jervine, several other alkaloids, which can be sepa concentrated tartaric acid failed to produce any change in rated by shaking the crude ethereal solution with aqueous the analytical numbers, whence the authors conclude that tartaric acid, and treating the mixed tartrates with soda) the substance is not a mixture of two bases, C33H45 NO.1 and a smaller bulk of ether: a residue is left, containing and C33H45NO1o

. The authors have named this base pseudo-jervine, an amorphous alkaloid named by the Japaconitine. It melts at 1850 to 186°, and closely, reauthors Veratralbine, and Jervine. Jervine, C26H3NO3, sembles aconitine. On saponification splits up into forms a sulphate almost insoluble in hot and cold water.

benzoic acid and a new base, Japaconin. Japaconin It crystallises with two molecules of water, melts at closely resembles aconin, but on treatment with benzoic 239°, and gives with sulphuric acid the same colours as anhydride it forms a tetrabenzoylated instead of a dipseudo-jervine; the sulphate of pseudo-jervine is, how; benzoylated derivative. A tetrabenzoylated body is also ever, tolerably soluble in water. The second

ethereal formed by heating japaconitine with benzoic anhydride, solution deposits on spontaneous evaporacion crystals of aconitine giving a dibenzoylated body. The authors adopt jervine mixed with another base, which forms a readily the following view as to the constitution of japaconitine, soluble sulphate. This base gives with sulphuric acid a admitting the existence of a basered colouration, hence the authors suggest the name Rubijervine. It melts at 237", and resembles in many respects

-O(C2H50) pseudo-jervine; forms with crystallised salts, and crystal.

-OH lises anhydrous as C26H43NO2. The ethereal mother

{ C26H39N0; }

-OH liquor of these crystals dries up to a varnish consisting

-OH

CHEMICAL NEWS, Reactions of Ammonio-chloride of Magnesium.
May 23, 1879.

225 having H4 more than aconitine, and constituted like

cent of nitrogen was present the method was not delicate aconitine and pseud-aconitine. The base Co6H88N2021 enough; the only plan was to obtain gold or platinum would be the triapo derivative of this hypothetical base, salts. thus

The next paper was read by S. U. PICKERING, "On the (C26H3, NO2) OC,H,O

Action of Hydrochloric Acid on Manganese Dioxide.” The

principal object of this paper is to criticise the conclusions 8

drawn by W. W. Fisher in a paper “On Manganese .

Tetrachloride (Chem. Soc. Fourn., September, 1878). C26H39N02 LOC,H30

The only conclusion at which the author arrives in

common with Fisher is that when manganese dioxide is Japaconine would thus be

treated with cold concentrated hydrochloric acid it disOH

solves, forming a dark brown liquid, which evolves (C26H39N07)=0.

chlorine slowly at ordinary temperatures, and more он

quickly when heated. The points in Fisher's paper are

stated by the author to be:—That from the liquid obtained Japanese aconite roots have already been examined by as above, water always precipitates a definite substance, Paul and Kingzett, who isolated a crystallisable base from which is manganese dioxide; that the ratio which the a small quantity of roots, which gave them numbers on precipitated manganese bears to the loosely combined combustion compatible with the substance being either chlorine of the higher chloride from which it is precipi. pseudaconitine or japaconitine. Unfortunately the small is as 1 : 2 atoms; that this higher chloride is MnCl4. yield did not enable them to fix its molecular weight by an The experiments, details of which are given in the present examination of the gold-salt, and consequently they adopted paper of 42 pages, prove, in the author's opinion, con. the formula C29H43NO, from combustions and nitrogen clusively, that from a solution of manganese dioxide in determinations by volume. Their description of the base cold hydrochloric acid, water does not precipitate a as not forming crystallised salts would rather indicate that definite substance; that the substance precipitated is not it was pseudaconitin. On the other hand, on boiling manganese dioxide, but a mixture of the dioxide with the with dilute sulphuric acid, a solution was obtained which sesquioxide in variable proportions; that the ratio which reduced Fehling's solution. This reaction does not occur the precipitated manganese bears to the available chlorine with pure pseudaconitine, although aconitine and japaco. of the choride from which it is precipitated is not nitine yield saponification-products capable of reducing 1 : 2 atoms; that the higher chloride produced is not Fehling's solution,

MnCl, but Mn2C16. The author in conclusion sums up In an appendix to the foregoing paper C. R. A. Wright briefly the main points proved in his paper as follows:and A. E. Menke describe experiments made to isolate When a solution of manganese dioxide in strong hydroif possible the hypothetical parent base referred to in the chloric acid is diluted with water, a mixture of oxides is previous paper. I cwt. of roots was worked up without precipitated which is indefinite in composition, varying adding any tartaric acid to the alcohol to prevent, if between 30MnO2,5 MnO and 36Mn02,5 Mno. The manpossible, dehydration. The crystallisable base obtained ganese contained in this precipitate as dioxide bears to was separated into several fractions, but all these gave the the loosely combined chlorine of the higher chloride from formula C66H88N2021 ; so that if the supposed parent base which it is precipitated the ratio 1 : 2 atoms. The total really exists in the roots, it must be much more easily de manganese precipitated therefore bears to this chlorine hydrated by heat, &c., during extraction than either aco- the ratio of about 1 : 1974 atoms. When the solution of nitine or pseudaconitine. In this and the other batches of the dioxide is performed in weaker acids the amount of roots extracted the authors confirm the observations of the higher chloride formed is not appreciably diminished. Paul and Kingzett as to the yield of alkaloids from Japanese An increase in the actual amount of the aqueous acid aconite, being nearly three times as great as that obtained employed for the solution is prejudicial to the stability of under similar circumstances from a good commercial the higher chloride formed; the solution of the dioxide sample of Aconitum napellus. The crystallised japaconi. and sesquioxide by hydrochloric acid, and the subsequent tin equals about i grm. per kilo., and the total yield of decomposition of the sesquichloride, being represented by alkaloids being 2 grms. per kilo., besides which about the following equations :I grm. of amorphous bases is retained in the alkaline liquors after repeated treatment with ether.

(1.) Mn2O3+6HCI= Mn,C16+3H20. Mr. Kingzett said that the Japanese aconite roots examined by Dr. Paul and himself were given to them by

(2.) 2MnO2+8HCI=Mn2Cl6+C12+4H20. Mr. Holmes to determine what alkaloids were present in these roots, and whether their composition agreed

*{Mn2Cl6+2H20=MnO2+MnCl2+4HC with that of the alkaloids from other aconite roots. As a result of their investigation they obtain a small quantity of a very pure alkaloid, quite crystalline, which had undoubtedly the formula C29H43N0g. The nitrogen was

*: y being usually as 6 to 1. determined by volume, a process which in his opinion was The Secretary then read a "Preliminary Note on more accurate than the soda-lime method. He could not some Reactions of the Ammonio-chloride of Magnesium agree with Dr. Wright in considering the formula wrong, | known as Magnesia Mixture," by H. D'ARCY Power. though the base did not form crystallised salts. On a The author has observed that most potassium and some previous occasion Dr. Wright had stated that their alka- sodium salts precipitate magnesium hydrate from a soluloid was pseudaconitin. This statement was now with-tion of ammonio-chloride of magnesium. Potassium drawn. They had obtained conclusive evidence of the iodide possesses this property in a marked degree. Thus existence of two alkaloids.

the addition of 15 c.c. of a io per cent solution of potasDr. Wright, in reply, said that he was not convinced sium iodide with 10 c.c. of ammonia to 5 c.c. of magnesia as to the identity or otherwise of his alkaloid and the one mixture (prepared by dissolving 5 grms. of magnesium obtained by Paul and Kingzett. From the data given by oxide in 40 c.c. of hydrochloric acid, and then adding the above authors he had stated that the properties, &c., 60 c.c. of ammonia and filtering), after standing twentyof their alkaloid agreed with those of pseudaconitin, and four hours gave a precipitate which, when washed and he still held to this statement. He had only withdrawn it ignited, weighed o‘046 grm.; it was pure Mgo, so that as far as his own alkaloid was concerned, which was cer- 46 per cent of the total MgO was precipitated. Potassium tainly not pseudaconitin. He did not dispute the accuracy bromide gave under similar circumstances a precipitate of ritrogen determinations by volume, but if only 2 per ( weighing o'002 grm. Further results are promised.

}

y{Mn2Cl6+3H20 =Mn203+6HCI }

226
Prevention of Ëscape of Sulphur Ĝases.

CHEMICAL News

May 23, 1879. The two following papers were taken as read :

The Society adjourned to June 5, when the following " The Composition of Cows' Milk in Health and papers will be read :-"On Gardenin,” by Dr. S:enhouse Disease," by S. Wynter BLYTH. The results of this and Mr. Groves; "On the Theory of the Frađional research are the separation of iwo alkaloidal bodies as Distillation," by F. D. Brown; On the Aaion of Organonormal constituents of milk; the separation of a substance, zinc Compounds on Quinons,” by F. R. Japp; On probably a glucoside, derived from plants, &c., eaten by Chlorstannic Acid,” by J. W. Mallet; "On Indigo-pur. the cow; a quantitative estimation of the different con- purin and Indirubin,” by E. Schunck; “Third Report to stituents of milk; analyse of samples of milk derived the Chemical Society on some Points in Chemical from cattle in an unhealthy state. The separation of the Dynamics," by Dr. Wright and Messrs. Luff and Rennie. milk alkaloids :- A litre of inilk is divided into three equal parts, to one of which a litre of water is added, the casein is precipitated in a Bocculent condition by the cautious addition of acetic acid, and, finally, by passing

CORRESPONDENCE carbonic acid, a clear yellow whey is obtained, which is separated by decantation and filtration and used to precipitate the second portion; the whey from this is DETERMINATION OF NITRIC AND NITROUS similarly used to precipitate the third portion of milk.

ACID. The yellow whey is boiled and filtered to get rid of albumen, and to the filtrate an excess of the solution of nitrate of mercury used for urea estimation is added.

To the Editor of the Chemical News. The precipitate which falls contains the two alkaloids, any Sir.-In the Chemical News, vol. xxxix., p. 205, Mr. Davis albumen, and urea as mercury compounds. It is washed quotes a remark of mine on Crum's mercury method and decomposed with sulphuretted hydrogen, &c. The (which Mr. Davis calls his method, although it was pub. first alkaloid, which the author proposes to call Galactine, blished many years ago, and used by several chemists pre. is thrown down by acetate of lead; the lead salt has the viously), as if I had not rendered justice to him. I had composition (PbO)2zC54H78N_045. Galactine is a white, certainly pointed out that the corre&ion for temperature brittle, neutral, tasteless, non-crystalline mass, soluble in and pressure is required for something less than "extreme water, insoluble in alcohol; it is precipitated by Sonnen. accuracy,” as Mr. Davis has put it, considering that it schein's and Scheibler's reagents. Excess of lead used to

arounts sometimes to more than 10 per cent, and I do not precipitate the galactine is removed and nitrate of mercury see that I can retract that. I have lately published tables added, which throws down an alkaloidal colouring matter. which allow these corrections to be made by a sinple read. Lactochrome, the empirical formula of the mercury salt, ing off, without any calculation (Dingler's Fournal, vol. HgOC6H18N06. Lactochrome is a bright red-orange ccxxxi.. p. 522). resinous body, softening at 100°, soluble in water and hot With reference to Mr. Warington's paper, read before alcohol. In addition to these alkaloids the author has the Chemical Society at its last meeting, I beg to point separated two substances. CH3O3 and C3H304, reducing out that in the Berliner Berichte, vol. xi., p. 439, I have copper solution, which he regards as decomposition described a number of tests, proving the accuracy of Crum's products of one substance, and as derived from food eaten mercury method for nitrous and nitric acid, for a mixture by the cow. They are obtained by precipitation with of both, and for mixtures with arsenious acid and with ammonia and tannin, after separating the above alkaloids. glucose. In the just.quoted paper in Dingler's Journal I The author gives the following as the average composi. have described some precautions required for correctly tion of healthy cow's milk Milk-fat, 3.50 per cent working the process with my“ Nitrometer.” (oleine, 1.477 ; stearin and palmitin, 1975; butyrin, oʻ270 ;

Although Mr. Davis cannot in any sense claim the pro. caproin, caprylin, and rutin, oʻ003); casein, 3'93; albumen, cess as his, yet I have to thank him for bringing it for0977 ; milk-sugar, 4'00; galactine, oʻ17 ; lactochrome, not

ward again, as I had entirely overlooked it before, and I determined; bitter principle, o‘or; urea, trace; ash, oʻ70 believe alkali works' chemists were generally in the same (K20, 0-1228; Na20, 0'0868; Cao, 0'1608; Fe2O3, 0.0005; situation, and are equally indebted to Mr. Davis. P2O5, Oʻ1922 ; CI, Oʻ1146; Mgo, 0'0243); water, 86 87.

Would you kindly allow me on this occasion to correct As regards milk from diseased cows the author concludes

an omission of a few words in my letter, printed in your that a cow suffering from even very acute disease may issue of the 2nd inst., which obscures the meaning of the give milk differing in no essential feature from normal passage. On p. 194, col. 2, line 5, it should stand" The milk, whilst local affections of the udder may often be total loss of nitre, apart from that in the chambers them. easily recognised. Analyses of milk from cows suffering selves." That this is the meaning of the passage is proved from mammitis, pneumonia, phthisis, &c., are given.

by the sequel.-I am, &c., Notes on the Effect of Alcohol on Saliva and on the

George LUNGE. Chemistry of Digestion,” by W. H. Watson. The author

Technical Laboratory of the Federal

Polytechnic Schools, Zürich, finds that ptyalin is more rapidly or effe&ually precipi. tated from simple aqueous solutions than from saliva. The separation is aided by heating to 100° F. 18 grs. | PREVENTION OF ESCAPE OF SULPHUR-GASES of absolute alcohol added to 200 grs. of saliva and

DURING THE 10 grs. of starch produced in an hour less extractive matter by about one-quarter than a similar mixture con

CHARGING OF PYRITES FURNACES. taining no alcohol; a similar reduction in the quantity of sugar produced was also effected by the addition of

To the Editor of the Chemical News. alcohol. The author made some experiments as to the Sir, Having erected a set of new furnaces and acid plant effect of slightly acidulating the mixture of starch and seven years ago in the neighbourhood of a town where saliva with hydrochloric acid. He arrived at the following some of the local authorities were hostile to the manuconclusions :-By the addition of a small amount of acid facture, it was therefore of the greatest importance to the action of the saliva is decidedly increased, while the prevent any escape of sulphur-gases. I was led to retarding influence of alcohol is not lessened by the study the best means of preventing

the escape during the presence of the acid. He also points out the bearing of time of charging. I hit upon a very simple and efficient these experiments on the process of digestion in the plan, which had the recommendation of costing nothing. stomach, where the starchy matters and saliva are mixed it was simply to close all the ash-pit doors before the with the gastric juice.

door of the furnace to be charged was opened. The neces. During the reading of the last three papers Dr. GILBERT sary draught being forced to enter through the only open took the Chair.

door entirely prevents the escape of gas, and the workman

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