Obrazy na stronie

And that with 5 c.c.

The composition of the hydrocarbons present, othe Free ammonia .. .. .. .. .. 0'0227

than marsh-gas, resembled hydride of ethyl, but the Albuminoid ammonia .. .. .. 0'0404

analytical volumes did not agree well in No.l. On com. The bottles containing the samples were kept freely ex paring No. I. gas with No. II. it is evident that the posed to daylight.

former contains a considerable proportion of nitrogen 5 c.c. of chloroform had therefore prevented all change, derived from atmospheric air, the oxygen of which had whilst 2 c.c. had been quite ineffectual, the free ammonia been used up to support the combustion of the fire-damp having risen tensold, doubtless at the expense of the ni. or the coal which was on fire. Owing to the plentiful trate contained in the water.

si:pply of air which reached the burning coal previous to During the first week the albuminoid ammonia had the colliery being fooded, it is possible that little if any somewhat increased in the latter sample.

carbonic oxide was generated, and the absence of this gas Chloroform in small quantities is therefore rather a in No. I., in which it was carefully sought, seems to show food than a poison to bacteria.

that the incomplete products of the combustion of the explosive mixture (the fire-damp which gave rise to the

explosion) had either in part been removed or so diluted COMPOSITION OF THE GAS WHICH ISSUED

with other gases that the carbonic oxide was present in FROM ONE OF THE SHAFTS OF THE

quantity too minute to be determined in the process of

analysis. The composition of No. II. is interesting. This ABERCARN COLLIERY.

consists doubtless of a mixture of blower-gases which By J. W. THOMAS.

found their way into the galleries through the channels

and cracks in the strata, and the gases evolved from the It will be remembered by those who have read the reports

working face cr other exposed coal. The latter gases of the terrible explosion which occurred at Abercarn on

would be naturally of similar composition to those which September it last, that in consequence of the coal having

escape under ordinary conditions of pressure and tem. taken fire close to the main shaft at Abercarn and in the

perature from a lump of coal exposed to the atmosphere. workings, and a direct communication between the upcast In previous papers “On the Gases Enclosed in Coal," and downcast being determined by the explosive force

Chem. Soc. Fourn., 1875-6-7, I have pointed out on more which destroyed the parting doors, it was soon discovered

than one occasion the curious fact that nitrogen escapes that it was advisable to Hood the colliery in order to

from coal in a vacuum at a proportionally quicker rate quench the fire. It will be remembered, too, that the

than any other gas. The flooding of the mine entirely colliers who were fortunate enough to escape with their

cut off the supply of air and consequently no nitrogen lives found their way out by the main winding shaft. The

could find its way into the galleries, admitting the possiAbercarn Colliery has three shafts or pits-two downcasts

bility of the oxygen being used up. It is evident, there. and one upcast. The main downcast and upcast, which

fore, that the percentage of nitrogen in No. II. is high, are 22 yards apart, are situated at Abercarn, and the other

and that this circumstance points to the probability of its downcast is at Cwm Carn, a distance of a mile and a

escaping from coal under ordinary conditions in the same quarter in a direct line, and two miles underground from

manner as it does in a vacuum. Before No. II. sample the upcast. As soon as the Abercarn portion of the was collected it will be seen from the analysis that all workings was filled with water, the gas issuing from the

the air had been swept out of the workings by diffusion coal and some of the products of combustion from the

with the gases evolved from the coal, and long before burning of the coal, and possibly more or less of the pro

the expiration of the nineteen days which elapsed between ducts of complete and incomplete combustion incidental the collection of No. I. and No. Il. all the products of to the explosion, were driven in the direction of the Cwm combustion would have been removed. During the Carn pit.' toward which the measures rise about 100 feet | nineteen days an average of more than 1,000,000 cubic or a little over 2 inches per yard. After the flooding of feet of gas was evolved each day, equal to the cubic conthe colliery was completed on September 16, when over tents of a large gallery or heading 51 miles in length. 40 feet of water were in the two shafts at Abercarn-a

My thanks are due to Mr. Pond, of Abercarn, for the large volume of gas, varying from 500 to 1500 cubic feet facilities afforded me in the collection of the gases and for per minute, was evolved until the water was cleared out his kind assistance. (about the middle of November) sufficiently low to admit The Laboratory, Cardiff, January 6, 1879. of a current of air being drawn in the direction of the upcast shaft. On September 20th last I collected some of the gas issuing from the Cwm Carn shaft, which was

ANALYSIS OF POPPY PETAL ASH. covered with turf with the exception of a hole in the centre occupied by an iron pipe in inches in diameter,

By C. J. H. WARDEN, F.C.S. through which the gas escaped. On both occasions the gas was collected in glass tubes previously fashioned for Analyses of the organic constituents of poppy petals sealing off the ends before a blowpipe flame--a double have been made by several chemists, but poppy petal ash ading syringe being employed to cause the gas to fill the has not hitherto, as far as I am aware, been examined. tubes by displacement. The analysis of the sample of Before giving results of the analysis of the ash, a few gas collected September 20 is marked No. 1. At the time remarks on the use to which poppy petals are put in the of collecting it 500 cubic feet per minute were evolved, the Government Opium Factories in Bengal may be interesting. temperature being 58° F. On October 9, I again collected 1 In the manufacture of opium for the China market gas, the composition of which is given in No. 2-about“ Provision Opium”-it is customary to envelope the 1200 cubic feet of gas per minute were escaping at the

soft opium in a shell composed of poppy petals technically time.

termed "leaves." Composition of the Gas in 100 Parts.

The petals are usually collected by noon on the third No. I. No. II.

day of ihe flowers' expansion, and Mr. J. Scott thus de. Carbonic anhydride .. 2954

scribes the process :-“ They clasp the petals at the base

2'43 Air / Oxygen .. .. .. 2673 none

with the forefinger and thumb, gently drawing them up. Nitrogen .. .. .. 10°32

wards, and tightening thern over the apex of the capsules, Marsh-gas .. .. .. 49:11


when the matured petals at once disarticulate or detach Hydride of ethyl .. .. 0-95


themselves. There is thus no tearing or straining of the Nitrogen .. .. .. .. 34'35 22:13

petals, and no loss of juice from the disarticulated sur.

faces.". 100'00

"Manual of Opium Husbandry,” by J. Scott.



The Uric Acid Group.

CHEMICAL NEWS 1 January 17, 1879.

The petals are then made into round"leaves" by spreading containing a certain amount of putrescent substances them on gentiy heated earthen or iron saucers, covering cannot have a great influence on the health of the inhathem with a moist cloth, and applying firm pressure by a bitants of the town, and remarked that even in science damp pad. “Leaves " vary in diameter from 6 to 12 ins., this question is nearly an open one, as it has been only and in thickness from o:5 to o'025 of an inch.

partly discussed. Indeed, it is a question if contaminated At the Patna Opium Factory 10 ozs. 94 grs. avd. of water, used for domestic purposes, can do any harm. The " leaves" are used for making the shell of each cake. The Professor remarked, also, that sometimes, for instance, in " leaves" are agglutinated round the opium by a 50 per consuming various cheeses we introduce at one time a cent mixture of opium in water.

quantity of putrescent matter into the stomach, which - Mr. Scott calculates that the annual consumption of would not be detected in the annual amount of water poppy petals is upwards of 16,000 maunds (one maund consumed, containing a large quantity of organic matters. equals 100 lbs. troy), to compose which the entire petals The analyses of the Neva water (by Professor Trapp) of no less than 4,710,400,000 flowers are required! During show that it cannot be called bad water :the season 1869-70 the Bengal Government spent £10,235 on leaves for the use of one factory. From the above

In i Cube Metre. short account of " leaves" it is evident that the poppy

Inorganic matter

32'25 grms. petal is an article of considerable commercial value.

Organic matter .. ..

23.00 The ash was prepared for analysis in the usual way, and


15:25 was of a light grey colour, and effervesced with acids. An MgCOZ

.. .. .. .. 740 1 aqueous solution gave indications of the presence of

NaCl .. .. .. . .. 1.60 » SOz, P2O5, C1, and K. All the determinations were by Na2SO4

2:40 gravimetric methods:


FeCO2.. .. .. .. .. .. 100 Parts of the Ash Contained.)

Al2Cl6 .. .. .. .. .. .. Ferric oxide, Fe202 3'0536

.. .. 0:50 1 Aluminic oxide, A1202 ..


M. Bertenson could not agree with the Professor. He Magnesic oxide, MgO .. .. ..


remarked that oxygen is very important in water, and Calcic oxide, CaO .. ..


certainly the more organic matter is present in the water Potassic oxide, K20


the less it contains of free oxygen. Potassic chloride, KCI ..


The committee decided to inspect the cemetery, and Sodic chloride, NaCl ...


take some water for analysis from the small river, and Sulphuric anhydride, Soz


then agreed to inspect also one of the bodies which was Phosphoric anhydride, P205..


buried the first on this ground. The conclusions of the Carbonic anhydride, CO2 .

5'4662 Silicic anhydride, SiO2 ..

committee will be of some interest, as there is not much .. .. ... 109551

agreement between the members concerning the question Sand ... .. .. .. .. .. .. .. 14:58 discussed. Charcoal .. .. .. .. .. .. ... I'1662


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1.20 2.60

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SiO2 ..



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THE URIC ACID GROUP. Percentage of the ash after deduction of the unessential constituents, carbonic anhydride, sand, and charcoal :

By SAMUEL E. PHILLIPS. Ferric oxide ..

.. .. .. 3.8647 Aluminic oxide ..

| As Mr. P. T. Main has advanced some new views of urea, .. .

12278 Magnesic oxide .. .. ..

.. . 5.6082

uric acid, and their derivatives, it may interest some stuCalcic oxide .. .. ..


dents of chemical philosophy if I give the substance of a ... Potassic oxide .. .. ..


| paper read before the British Association of 1877. “ On Potassic chloride . .. .. .. .. 12'2867

the Principle of Uric Acid Genesis." Sodic chloride .. .. .. .. .. .. 1*2071

“As the vast and complex researches of Liebig, Strecker, Sulphuric anhydride


Baeyer, and others have now culminated in the studies of Phosphoric anhydride ..


M. Grimaux, it is thought to be high tinie to trace herein Silicic anhydride .. .. .. ..

the plain indications of law, order, and symmetry in lieu

of empirical confusion." The author refers to a paper on 100'0000

the constitution of uric acid (Chem. News, vol. xxxii., na Opium Factory, September 9, 1878.

p. 209), and now maintains that a clear view of the chemical laws involved in - 2HO, under varied conditions, will supply the key to unravel the endless empirical con

fusion. IS CONTAMINATED WATER INJURIOUS FOR Starting with eight acids, it is maintained that under DOMESTIC PURPOSES ?

the combined influence of heat, time, and pressure that

all these, and some others, act similarly upon urea, and By SERGIUS KERN, M.E., St. Petersburg.

condense with successive eliminations of -2H0, in pro

portion to the strength or duration of the applied condi. The St. Petersburg town council organised a committee

tions :for the discussion of the following question :- About seven Hydromellitic acid (?) .... CAH,02,0. HO miles from the town a new cemetery was opened some Glycollic acid .. .. .. .. C4H204,0. HO years ago. A small river runs from this place into the

Glyoxalic acid .. .. C4H,04,0. HO Neva, some eight miles above the town. It was found that this small river is entirely contaminated by the de.

Glyoxylic acid .. .. .. .. C4H306,0. HO composition of the bodies. Owing to this inconvenience Unknown acid .. .. .. .. C6H,02,0. HO many propose to close the cemetery. The discussions Pyruvic acid . .. .... C6H304,0. HO which took place in the sitting of the committee on No. Malonic acid .. .. .. .. C6H,04,0.3HO vember 23, 1858, are rather interesting, as the sanitary Tartronic acid .. .. .. .. C6H,06,0.3HO improvements of the town are still considered secondary questions.

That with these, eight ureide series may be projected, M. Borodin, Professor of Chemistry, thinks that water lembracing very much that is already known, and presenting


The Uric Acid Gronp. January 17, 1879.7

some blanks, which may easily be attained in the future, (c) Is the hypothetical first stage of the di reaction. and that these eight series may be thus epitomised, (d) The second stage is allantoin, and the formula o assuming 1 equivalent of acid in each case :

production is precisely that given by the dis+ Urea -2H0=(CO)2RH3N2=the R urea (a)

coverer, M. Grimaux. It also corresponds with -4H0=CyRHN=the cyanamid (0)

M. Grimaux's Pyruvil in the pyruvic series, or +2Urea - 2H0=(CO)RH N4=the di-urea (c)

with my pseudo-uric acid in the tartronyl series. - 4H0=(CO)2CyRH Nz=the pseudo-uric acid(d) |

(e) Is the ultimate miscalled “mycomelic acid " and -6H0=Cy2RH3N2= the ultimate (e)

the perfect analogue of uric acid. It is remarked that these uric acid ultimates are not

One word more as to the bizarre character of these strialy such, and the two extensions of variety are ex- | misleading notations. cluded from the brief terms of the paper :- First, certain

The discoverer of “melid acetic acid ” thought it was obscure cases where these radicals are affected by

| an aceto body, and that it was an acid, and hence the reaction with ammonia – 2HO, as in hydrazulmoxin and

terminal (COOH) so fashionably characteristic of acid hydrazulmin; secondly, the more complex forms of ureide

types! Of course the pretence is that these structural condensation obtained by M. Grimaux, which all, never

or graphic portraits are intended to delineate certain theless, prove to be grand illustrations of the same definite

features of genetic or analytic behaviour in the compounds. laws.

The plain fact is, however, that it is a mischievous device It follows that all the (a's) are normal ureas, though

of wanton hypothesis, and hence our exposure of the often associated with confused names in their empirical

true nature of that body, as containing no acetic acid in discovery ; that all the (b's) are R cyanamids, though not

its genesis, and no acid behaviour in its derivatives. It is at all recognised as such, and some of them are called

a substituted mellamine base! (See CHEMICAL News, vol. ureas; that the ureides or di-ureas have three stages

xxxiv., p. 13.) ending in uric acid and its other analogues ; that the law

When M. Grimaux speaks of glyoxylic acid he means of elimination has three aspects :

glyoxalic acid, and his notations correspond with his

remarkable synthesis of allantoin : but Mr. Main, rightly 1. When hydrates condense into each other, or into an estimating the total elements of glyoxylic acid, gives ammonium, as thus

allanturic acid as one of its derivatives, which is a double Alcohol, C4H5,0.HO+HH2N-2H0=C4H5,H2N mistake. First, as a matter of chemical fact ; and,

secondly, as a matter of notational display. 2. When successive elements of ammonia are super Allanturic acid is “glyoxalyl urea." "Why, then, justify added to the condensation, each step is attended with an

its early misnomer by an acid notation ending in (COOH) additional - 2H0 by derivation from the radical when no hydrate subsists. A wonderful regularity may be traced

Glyoxylic acid

(Снноно in the glucoride researches of M. Schiff, by which for illustration,


Allanturic acid Esculetine anilide is .. (C18H306)PhHN

(CHHONHCN The di-anilide .... (C18H304)Ph2H3N2

1COOH The tri-anil.. .. .. (C18H,02)Ph3H3N3

And why notate it with cyanogen as a constituent ? And a recent research of M. Ladenburg's, where hydrates

Under the derivatives of tartronic acid we haveare "condensed into toluylen diamine, affords a striking illustration, the more so, as given like the former, on em Dialuric acid pirical and independent grounds.

CONHCN "3. When ureas condense into ureides, the tendency,

CHHO after eliminating - 2HO for each equivalent of acid or

hydrate, is for each (CO)2 to change into cyanogen with Violuric acid
elimination of 2HO, as typified in the well known case-

Urea -2H0 = cyanamid

(6) CH(NO)


(a) is tartronyl urea, (CO)2C6H,06H3N2. Both (a) and I am much pleased to find that I am not alonein entertain. (b) are given with the acid terminations to correspond ing the cyanamid character of uric acid; but the idea of in with tartronic acid; but it is quite overlooked that (6) cluding urea in the same category, as a derivative of uric | belongs to another acid series, for it is known to be a acid, is certainly a confused and illegitimate sketch of “malonyl urea.” hypothesis.

How, then, does it happen that so many amides should The ammoniacal character of urea is established beyond be called acids? The answer is plain, and the parentage question ; its amide dedoublements and their basic cha- is clearly traceable to a mistaken hypothesis of the early racters admit of no other explanation.

discoverers, which is grossly perpetuated to this day. M. Dreschel, in obtaining several varied cyanamids, They noticed among these bodies a tendency to combine notates one as the hydrochlorides." It is therefore clear with or to assimilate metal ingredients, and the notion that he might have obtained the hydrate. Besides, hy. was that the relation subsisting was that of acid and base. drates of dicyanamid and others are known, but surely no It is, of course, familiar that many hydrocarbons have one expects to find them ureal.

a tendency which is notably typified in acetylen; and we Mr. Main falls into a mistake, which his notations ought now find that the same tendency is frequently evinced to have corrected; but, alas! they are only fitted to mis among amides; but the wonder is that modern chemists lead. Allantoin is not a derivative of "glyoxylic acid," should be so slow in establishing a just discrimination. as may be seen thus:-

Were we to imitate Mr. Main's ureal hypothesis, and Glyoxalic acid CAH,04,0.10=glyoxalyl urea

contend that ammonia was an acid, and that the amides + urea --2H0=(CO)2C,H,02H3N2 (a)

of Zn, Cu, or K were its basic salts, the idea would neces

sarily be scouted ; but the same principle is largely and -4HO=CyC4H10.HN (0)

widely indulged in throughout the inodern types of organic , +2 urea -2H0=(CO)AC4H104H NA (C)

chemistry; and we constantly read of amido acids, and is , - 4H0=(CO)2Cyc,H,OH N2 (d)

see their terminal (COOH) graphically displayed, while -6H0=Cy2C4H04H3N2 (e)

the context ir. so many cases reveals the fact of their (6) As urea -2H0 becomes cyanamid, so glyoxalyi basic charaders, as seen in their "hydrochlorides," their

urea - 2HO becomes glyoxalyl cyanamid.' sulphates, nitrates, and other salts.


Rozan's Process for Desilvering Lead.

I CHEMICAL NEWS, 1 January 17, 1879.

I care not to follow Mr. Main when he seeks to paint , tile sulphur and the sulphur contained in the ash. Perhaps the lily, and to improve his bizarre notations by atomicity it might be interesting to the members if Mr. Pattinson equations and “more symmetrical" portraits of the atomic would explain how the amounts of these latter are deterdispositions. But the body selected for all this display / mined. is wisely chosen from the least understood of chemical Mr. PATTINSON-It is very quickly done. The total compounds, viz., the amorphous substance called sulphur is determined in the usual way, by oxidation ; “hydrazulmin."

then the amount remaining in the ash of the coal is deterIt may or may not be a definite chemical body ; but as mined, and the difference of these two amounts gives the I have done my best, in a known and legitimate way, to volatile sulphur. The sulphur in the ash is retained by arrive at some faint à priori understanding of its genesis virtue of the lime which the ash contains, which probably and relations in a yet unpublished “Study of Ureide existed originally as carbonate. I may perhaps mention Derivatives," it may be well to compare notes as to our here the method used to determine the total sulphur in methods of investigation. One is playing with skittles, the coals. The oid method, by heating with strong and can place them in any position, only controlled by / nitric acid and evaporating to dryness, is very incorrect, certain laws of the game, such as the atomicity rules, &c. never yielding more than a fraction of the sulphur really The other is rather a student of the actual chemical contained in the coal. The method by deflagration with forces involved, and has comparatively a very limited nitre and salt is very correct when carefully done, but it number of pieces. He can only place on the board defi requires great care, both in the deflagration and in the nite or well known radicals, and these only in certain subsequent precipitation of the sulphur as barium sul. limited modes of relationship, while from an infinitude of phate. The method now used, however, is very much " residues" he is utterly debarred.

simpler than any of the old ones : a weighed quantity of With one it is an easy matter to build up on paper a the coal or coke (about 20 grains) is mixed with one and melid-acetic acid, or an allanturic acid, with wrong mate- a half times its weight of slacked lime, moistened slightly rials; with the other these feats are simply impossible. with water, and then heated in a muffle at a red-heat. One is so confidently assured that he can open out the The carbon burns off, and the sulphur is converted into condensed types to graphically exhibit the internal play calcic sulphate, which is then dissolved in hydrochloric of atomicities, and go yet further in the Frankland school acid, and the sulphuric acid precipitated in the usual way. to "more symmetrical” pictures. The other has to retire Mr. H. L. PATTINSON-What is the reason that the in all humility, simply confessing inability to either method of treating with nitric acid is unsatisfactory? execute or understand such works of art.

Mr. J. PATTINSON-Probably a portion of the pyrites is “We have referred to the uric acid analogues as covered and protected by the coal, even when it is very ultimates. That term, however, admits of some qualifi. finely pulverised. cation, because by another mode of reaction it is possible The PRESIDENT-If no member has any more remarks to reduce the radicals of the varied acids, and in that to make we will proceed to the discussion on Mr. Dunn's respect to realise more ultimate compounds.

paper, “On Indicators in Alkalimetry." I do not know if “Mycomelic acid,", CyC_H,02H3N2(a)

Mr. Dunn has anything further to add on the subject of

his paper. (a) +H3N-2H0, hydrazulmoxin,Cy2C,H,02H2(NH2)N2 (6)

Mr. Dunn-I have not done anything more in the (6) +H3N - 2H0, hydrazulmin,

| matter since the paper was read. I may just mention, Cy2C4H,OH(NH2)2N2 (c)

| however, that aurin does not keep quite so long as litmus.

It will, however, keep for two or three months without It only remains to notice that this hydrazulmoxin is | alteration, and the preparation of the solution is so easy identical or isometic with Mr. Main's “azulmic acid." that it can be made afresh every two or three months with

That in each of these stages of reaction one equivalent very little trouble. of ammonia is added is a chemical fact beyond question ; The President, in calling on Mr. Cookson to read his and that each stage implies a theoretical tendency to paper, “On Rozan's Process for Desilverising Lead," - 2HO is a principle I have tried hard to exemplify, and said, I had the pleasure of going down to Messrs. Cooknced not here repeat the grounds, while gladly referring son's works, at Willington, a few weeks ago, and I think to the actual facts of analysis in confirmation.

I have not for a long time been in any works which were more interesting, both from a chemical and a mechanical point of view. The handling of large quantites of lead

is done almost entirely by hydraulic machinery, which I PROCEEDINGS OF SOCIETIES.

have no doubt saves a large amount of money formerly spent in wages for hand labour. The paper to come

before us to-night is one of very great interest, and perNEWCASTLE CHEMICAL SOCIETY.

haps, if we say anything about it now, it must be to General Meeting, November 28, 1872.

express a kind of regret that a patent is likely to come

into operation which may do away with the classical proMr. R. C. CLAPHAM, President, in the Chair.

cess of Mr. H. L. Pattinson-a process for which the North of England has long been justly celebrated.

"On Rozan's Process for Desilverising Lead,” by Mr. The minutes of the previous meeting were read and con Cookson.-In attempting to describe the leading features firmed.

of the Rozan system of desilverising, I must ask you to The following were elected members :-Mr. Walter

bear in mind that in principle it is in most respects idenWeldon, Dr. Bernard Mohr, Mr. John Watson, Mr. Thos.

tical with the well-known process of the late Mr. H. L. Campbell, Mr. John Hope, jun., Prof. R. W. Atkinson,

Pattinson, always excepting that in the former case Mr. Mayfield, Mr. J. W. White, Dr. H. E. Armstrong, cranes and steam supersede the more expensive system of Mr. T. Crawford, Mr. W. G. Strype.

manual labour employed by Mr. Pattinson. In both The following name was read for the first time :-Mr.

cases, however, the whole working depends on the fact John Cliff, Runcorn.

that as melted lead cools the first-forming crystals contain The President-Our first business, gentlemen, is to less silver than the portion remaining liquid, and that in proceed to the discussion on Mr. Pattinson's paper, " On the usual way of working by thirds this exists to the the Quality of the Small Coal used on the Tyne." It is extent that when two-thirds of a given quantity is in a very valuable paper, especially as regards the amount | crystals and one-third liquid, the two-thirds will actually of sulphur contained in the ash. I do not remember contain only half the quantity of silver that the one-third having before seen results set forth to show both the vola. I or lesser quantity does. In the Rozan system steam is used with a double purpose, one of which is mechanical might give a little more account of. When I saw Mr. and the other chemical. The mechanical effect is to boil Cookson's works the condensation appeared very perfect up and violently stir the melted lead, thus preventing any and free from escape. setting on the surface; and this boiling of the steam Mr. COOKSON-It is not a point of much importance through the lead as it cools causes a regular crystallisa whether the condensers are air-tight or not, because we tion, and an easy and perfect separation of the liquid from | have a draught at the far end, so that there is always an the crystals when the proper stage is reached. The inward suction. In practice we find that in the last chemical effect is due to the oxidising action of the steam chamber there is little or no settling. I have sometimes on the antimony, copper, iron, arsenic, and other extra- opened the door and gone in, but could never observe any. neous metals, which, being converted into oxides, are thing except steam in the state of fog or cloud. The either skimmed off or carried away with the escaping oxides of antimony and copper are partly skimmed off the steam, and afterwards allowed to settle in the condensers. melted lead as dross, and partly condensed as fume in the This chemical action fulfils so good a purpose that the chambers. The fume near the furnaces contains a larger Spanish rich silver leads are desilverised without any quantity of these oxides, and as it gets further from the previous calcination, and an unusually pure market lead furnace it approaches more and more nearly in composi. is produced from them. Even in the case of Greek lead tion to pure oxide of lead, thus confirming an old dictum only a partial calcination is required, as experience shows of lead-smelters, that oxide of lead is more difficult to that a portion of antimony, equal to about per cent, condense than the oxides of the accompanying metals, existing in the original silver lead, is an advaotage, inas. One thing I did not mention, which has indeed nothing to much as this small quantity of antimony has a remark. do with the subject of the paper, but is simply a mechan. able effect in reducing the quantity of lead oxides formed, ical arrangement-our system of cranes is very perfect. Without absolute proof it may be premature to speak of From the time when the crude lead enters our works to any chemical action, as it is possible the whole of the the time when it makes its exit as “market lead" it is oxidation is due to the mechanical exposure of the molten hardly ever touched by hand, but listed from place to place impure lead to the influence of the atmosphere, assisted | entirely by hydraulic cranes, which costs very much less by the air carried into the pot by the steam; but I am than if it were lifted by hand. strongly of opinion that a chemical action actually takes Mr. GLOVER-In blowing the steam through is there place. The leads most suitable for the steam process are any chemical decomposition of the steam, or is the action of a similar class to the already-mentioned Spanish rich simply mechanical ? Are the copper and antimony silver leads, containing from 3 to 4 per cent of foreign oxidised by the steam, and the oxides volatilised, or carmetals, of which antimony generally constitutes fully ried off mechanically? two-thirds of the quantity. In the old Pattinson process Mr. PATTINSON—To a chemist the most interesting those extraneous metals are eliminated as far as possible point in the process is that which has just been mentioned by a previous calcination, the charges sometimes requiring by Mr. Glover. I am inclined to think that at such a forty-eight hours in the calcining furnace in order to fit temperature the copper would not be volatilised. Could them for the pots. In the Rozan system, however, this | Mr. Cookson tell us the composition of the fume concalcination is dispensed with, and the lead as it comes densed near the crystallising pot? I think that as the out of the smelting furnaces is used direct by the desilver. oxides of copper and antimony accumulate on the top, ising apparatuses.

they are most likely to be mechanically carried away to Having described the working of the plant, I will put the condensers. The question is, is the steam decombefore you as shortly as I can the advantages and defects posed, is hydrogen produced, or is the oxidation due to of the Rozan as compared to the Pattinson system as the atmosphere?

Mr. Cookson, I think it is due principally to the free The advantages the Rozan system possesses are

oxygen which is always contained in small quantity in 1. The entire saving of the cost of calcining all ordi. the steam, and that the oxides are then carried away by a

narily hard leads, and in the case of extra hard ! purely mechanical action.
leads, such as Greek lead, a very large saving.

Mr. B. S. PROCTOR_Have you ever had any trace of 2. A cost for labour not exceeding one-fifth.

| hydrogen ? 3. A cost for fuel of about two-fifths.

Mr. Cookson—I have put my nose into the condensers, 4. A saving of one-third in the oxides produced, which thinking that if hydrogen were produced there would be a advantage any lead manufacturer will fully appre

certain quantity of arseniuretted hydrogen formed, but I ciate.

have never smelt any. There is a trace of sulphur found Its defects are

in the condensers, but I never smelt any sulphuretted

hydrogen. 1. A large capital outlay.

Mr. H. L. PATTINSON-Have you ever tried air instead 2. A constant expense in repairs and renewals.

of steam? The repairs are only a small matter, but until lately the Mr. CookSON-It is included in the patent, but it in. cost of renewal of pots was a very serious and heavy creases the quantity of oxide of lead formed very greatly. item: it is one which by observation and care we have Mr. GIBB said, it appeared to him that the action of the been able very considerably to reduce. In 1876 pots cost steam was purely mechanical, not chemical, and that the us over 35. per ton of market lead; in 1877 it came to i process was merely the Pattinson process with improved 28. 2d.; and this year, so far, the cost has been further mechanical arrangements. reduced to is. 4d. per ton.

The President wished to remind Mr. Gibb that most On the whole, the advantages are very considerably of his objections had been already answered by Mr. Cookgreater than the defects of the Rozan system; and I can son in the paper itself. confidently assert that our firm has every reason to be Mr. Cookson-I so far agree with Mr. Gibb that I often satisfied with having adopted it.

call the process - Mechanical Pattinsonisation." The The following is a table showing silver assays of twelve steam may perhaps be described as a vehicle for conveying crystallisings taken from an average of 350 operations : the oxygen of the air in limited quantity to the lead. Ounces per ton of lead.

Mr. PATTINSON-Or a valuable means of getting the

niechanical effect of air with a smaller proportion of 570 315 202 112 62 331 191 10 5 21 13 14 dwts. oxygen.

The PresideNT_Would any member like to ask Mr. Mr. MORRISON—The steam protects the lead ? Cookson any questions about the paper ? Mr. Morrison Mr. COOKSON-No; for if we work soft leads we find, has referred to condensation, and it struck me that that with all our care, that the quantity of oxides produced is was a point which, at the present meeting, Mr. Cookson 1 largely increased.

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