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out taking certain precautions. The rough glass plate | must have been recently washed, so as to saturate with moisture the absorbent substances which exist in the depressions of the glass, and which are not rubbed off when the surface is wiped dry. If these are allowed to dry thoroughly they start crystallisation in the depressions of the plate; the crystals grow sometimes very rapidly, sometimes very slowly. In the latter case scratching with a sharp point brings the crystals into contact with the solution, which solidifies at once.

This may account for a good many of Prof. Tomlinson's negative results. It also explains his statement that drawing a sharp edge across the drops generally makes them crystallise. If the plate is in the right condition, they do not do so. I have drawn sharp points across hundreds of drops of the strongest solutions in all kinds of weather without causing crystallisation.

It is also necessary in the case of the alums or sodium acetate to clean the sharp point after every experiment with boiling water or preferably a red heat. Cold water and wiping will not generally clean a penknife for instance, owing to the great adhesiveness of the salt.

Next, with regard to rubbing with oil, which is really the crucial test for Prof. Tomlinson's theory, he seems to have been satisfied with rubbing the sulphate with oil on a glass plate; he very naturally found that it crystallised. I had extreme difficulty at first in getting this experiment to succeed, and I could not do so at all in my laboratory, where the dust possibly contains sodium sulphate. But I did succeed completely in another room.

However, if Prof. Tomlinson will wash his hands he may do what I have just done, i.e., rub a little castor oil on the palm of the hand, and then rub in drops of a 3 to I solution of the sulphate without its crystallising. He may repeat this with sodium acetate of any strength. Strong sodium carbonate will give a modified salt which is quite inactive in a 6 to 1 solution, and is, therefore, neither the normal nor 7-atom salt. I have succeeded with the alums also, but they are difficult to manage.

Secondly, as direct evidence against the absorption theory, Prof. Tomlinson gives the following experiments: Three pieces of dried sponge were introduced into flasks of the sulphate, and were inactive. Of course they were, being saturated at once. Curiously enough, he actually describes the converse of this experiment, which is needed to maintain my theory. He found some years ago that when sponge is drawn rapidly over the surface, the solution crystallises on the sponge, while that in the flask did not. The only inference he draws from this is that results are often contradictory.

He mentions one more fact as bearing on this point. A solution of the sulphate crystallised when poured on the soil of his garden. This is the very same experiment which first led me to work at the absorption theory. I found, as described in Nature, that lumps of earth could be put freely into the flask; but I also found that every single drop put on the earth in the beds crystallised at

once.

Similarly with regard to the third point, the effect of sudden jars, Prof. Tomlinson gives experiments which simply confirm my results. He begins thus: "There is one point upon which all observers down to the time of Mr. Grenfell are agreed, namely, that if a supersaturated solution boiling in a flask be tied over with bladder and left until cold, it will, if the bladder be pierced, immediately become solid. Indeed, this has long been a common lecture-room experiment. But Mr. Grenfell goes far beyond anything I or previous observers have done; he exposes these solutions, &c." He thus distinctly implies that I have denied the fact. Of course I have never denied it at all. In my first paper in the Proc. Roy. Soc., two years ago, I carefully explained that I had been driven to abandon cotton-wool, which was generally recommended as a covering, because I felt convinced that in removing it I shook down some crystals. I added that by using loose paper covers I found that the solutions very

seldom crystallised when uncovered. Having thus saddled me with an opinion I have almost expressly repudiated, Prof. Tomlinson proceeds to upset me by the following evidence. He took two flasks of the sulphate; pierced the bladder of one, and it crystallised; he removed the cover of the other in the country, and it remained liquid during a long walk. This, as usual, supports my views. Removing the cover quietly is a very different process to piercing with a pin, and no crystals were shaken down. In the same way he shook a solution of alum several times without shaking down any crystals, but piercing with a pin was effectual. Alum is an adhesive salt, and requires a jerk to be given. Again he pierced the bladder of two flasks of the sulphate, and only one crystallised. On increasing the opening next day to the size of a pea, the other solution crystallised in a few hours. Possibly an absorbent nucleus got in through the enlarged opening, but it is more probable that the crystals round the opening effloresced and some fragment fell in. I have found the effloresced sulphate invariably active. In air it never gets quite free from the normal salt. To sum up: the great majority of the experiments described in this paper confirm my theories. Prof. Tomlinson arrived at negative results in other cases from not knowing the precautions which have to be taken.

The fact that paper, earth, and all kinds of substances can be introduced into the flasks; that drops will remain liquid on all kinds of surfaces for hours; even granting, which I do not, that it is only in wet weather, and the experiments with oil are absolutely fatal to any theory based on preferential adhesion of the salt to a greasy surface.

The immediate production of the modified seven atom carbonate by blotting-paper, the experiments with sponge and earth, the effect of damp weather on aërial nuclei, and a multitude of similar results which I could give if necessary, are incapable of explanation on any other theory than that of the abstraction of water by absorbent bodies.

The old theory which made the air a store-house of all kinds of crystals is dead and buried. I frequently have half a dozen plates covered with drops of various solutions exposed to air in my laboratory for hours or days, and the drops evaporate quietly as modified salts, or remain liquid. The minutest trace of a crystal makes them crystallise at once.

UPON THE ALTERATION OF STANDARD AMMONIUM CHLORIDE SOLUTION WHEN KEPT IN THE DARK.

By ALBERT R. LEEDS, Ph.D.

IN February, 1877, MM. Schloesing and Muntz communi. cated to the French Academy (Comptes Rendus, lxxxiv., 301), the results of elaborate experiments tending to prove that nitrification was due in certain cases to the action of an organised ferment. They further showed that nitrification could be arrested in such cases by the vapour of chloroform, and would not set up again until after the filtered sewage employed had been freshly "seeded" by the washings of a soil which was known to nitrify. These observations were verified and extended by R. Warington (CHEM. NEWS, xxxvi., 262, 1877), who showed that chloroform and carbon disulphide effectually prevent nitrification in certain cases, while carbolic acid is probably effective to the extent in which it comes in contact with the soil. Moreover that the action of the nitrifying body does not occur at all in the light, darkness being apparently essential. In a note upon the ferment theory of nitrification, by Prof. F. H. Storer (CHEM. NEWS, xxxvii., 268), he states that a solution of ammonium chloride, which had been prepared ten or twelve months

18

Working of Mild Steel.

previously, gave a strong reaction for nitrites. It had been preserved in a half-filled glass-stoppered bottle, put away in a dark cupboard. Similar solutions, seeded in various ways, but left in a strong light for a number of months, gave no reaction whatever for nitrites or nitrates. The following experiments confirm these results, so far as the change of the ammonium solutions in the dark is concerned, and give the rate at which it may expected to occur under ordinary circumstances.

A standard solution of ammonium chloride had been prepared October 15th, 1877, by dissolving o7867 grm. NH4Cl, purified by repeated sublimation, in a litre of re. distilled water, free from ammonia. Another solution was prepared by diluting 100 c.c. of this water to 1 litre, and used constantly during the months of October and November, 1877, in making the estimations which will be found recorded in an article entitled "Contributions from the Laboratory of the Stevens Institute of Technology." They were put aside in a dark closet, and remained there until this autumn, when a new standard ammonium chloride solution was prepared from the fear that the old solutions had altered. This proves to have been the case. A careful determination, as ammonio-platinic chloride of the ammonia contained in 250 c.c. of the stronger solution, gave o'0575 grm. or o'00023 grm. in I c.c., instead of 000025, the amount which the solution originally contained. Instead of being perfectly limpid, as it was when made, the solution contained a number of white filaments, looking like the vestiges of some vegetable growth. The more dilute solution presented the same appearances, but not to so marked a degree. 25 c.c. of the solution were used in the examination for nitrites, but their presence could not be shown in this large quantity of the liquid. 5 c.c. of the solution were evaporated three times to dryness in a platinum dish with o'i grm. of caustic soda, prepared from sodium,, and which had been found entirely free from nitrogen compounds. It was then distilled with 6 grms. pig-iron in a vessel entirely made of glass, the pig-iron having been previously repeatedly distilled with water, until it and the vessel had ceased to give any reaction for ammonia. The distillate contained o'03 m.grm. H3N equivalent to o'11 m.grm.; HNO3, or o‘022 m.grm. ; HNO3 per cubic centimetre.

ACTION OF POTASSIUM PERMANGANATE

UPON OXALIC ACID.

By ALBERT R. LEEDS, Ph.D.

IN a paper entitled "Ozone and the Atmosphere," I stated that when the two solid substances, crystallised oxalic acid and potassium permanganate in powder, were mixed together, they liberated ozone on addition of water. Vacation intervening, the study of this and similar reactions was not resumed until five months later, in October of last year, when it was found that other organic acids yielded the same apparent results, more especially tartaric and acetic acids. The deportment of the inorganic acids varied: nitric acid, added to potassium permanganate, liberated a gas plenteously, which affected the potassium iodide papers, but the gas evidently contained nitrous acid, and when passed through water had no effect upon the test papers. Hydrochloric acid gave negative results, but chromic acid produced with the permanganate an apparently copious evolution of ozone.

An attempt was then made to determine the amount of ozone apparently given off. 20 grms. of pulverised oxalic acid were introduced into a half-litre flask, which was provided with a glass-funnel and stopcock for the introduction of a saturated solution of potassium permanganate, and an exit tube connecting with a wash-bottle con

Proceedings Amer. Chem. Soc., vol. ii. + CHEMICAL NEWS, xxxviii., p. 224.

CHEMICAL NEWS,
January 10, 1879.

taining water. The corks used in this and the other experiments were boiled in paraffin, and the joints luted with the same. The escaping gas, after passing through the wash-bottle, was made to traverse a Geissler absorption apparatus, containing a decinormal solution of potassium iodide. The action was allowed to go on for a week at common temperatures, the permanganate being added in successive portions until the oxalic acid was completely decomposed. Nine litres of air were drawn through the apparatus, after which the flask was gently warmed and 9 litres more of air drawn through it. No change whatever had taken place in the potassium iodide. The entire experiment was carefully repeated with identical results.

water.

This unexpected conclusion threw suspicion on the methods of ozone-generation, in which potassium permanganate is decomposed by an acid, and more particularly that in which sulphuric acid is employed. For this reason the same apparatus was used as in the above experiment, but 25 grms. pulverised permanganate were introduced into the flask and sulphuric acid run in through the funnel a drop at a time. Much caution was used in conducting the operation, but even then one flask was blown to pieces, after the reaction had been going on for several hours. In each of three trials the potassium iodide remained unchanged, but chlorine was found in the washThis led to an examination of the reagents employed, with the result of finding that the potassium permanganate contained o'164 per cent of potassium nitrate, and 7:47 per cent of other impurities, principally potassium chlorate, but along with it some manganic oxide, insoluble silicious residue, and a minute amount of potassium chloride. A trace of chlorine was likewise found in the oxalic acid. Analyses of other nominally chemically pure preparations were made with similar results, the least impure containing 97.06 per cent potassium permanganate, with o'148 per cent chlorate, a trace of chloride, some manganic oxide and sand. The percentage of manganese, in the potassium permanganate first spoken of, determined gravimetrically by precipitation as sulphide, solution in hydrochloric acid, re-precipitation as caibonate and estimation as proto-sesquioxide, was 31.50 per cent, instead of 34'66, the theoretical amount. The manganese percentage determined volumetrically by means of ammonio-ferrous sulphate was 32.78, showing the influence of the admixture of chlorate upon the oxidation of the iron.

At this stage of the enquiry I found that the same sources of error had previously been exposed by C. Rammelsberg (Berichte der Deutsch. Chem. Gesell., vi., p. 604), who showed that the potassium permanganate, which he experimented upon, contained only 27.3 per cent of manganese, the difference being due to 21'6 per cent of potassium perchlorate. He also found that when the permanganate, free from chlorine, was used, no smell was developed by the action of sulphuric acid, and the reaction upon iodo-starch was so weak that it evidently arose from a trace of chlorine.

ON THE WORKING OF MILD STEEL.
By SERGIUS KERN, M.E,, St. Petersburg.

MANY experiments prove that mild steel, before being rolled into plates or bars, may be heated to a light welding heat, without the least fear of the ingot crumbling into pieces, which often happens with burnt steel. Altogether many persons are rather afraid of this method of working steel, and prefer to heat the ingots only to a white non-welding heat. This inferior mode of working has given rise to a large percentage of bad products, especially when plates are prepared, and plates with surface defects are certainly rejected. For cheap boiler and ship plates Bessemer steel is at the present time in constant use, and

the chief difficulty in obtaining clean plates in this case are the numerous blow-holes found in the outer parts of the ingots. The rolling of such ingots only masks these defects to a certain extent, as the small marks of their presence in the ingot may be always found in the finished plate. Often slag, scale, and small pieces of sand or brick laying on the surface of the ingot while it is in the furnace fall down into the blow-holes, and are rolled together with the ingot; such plates, with slag and brick particles rolled into the metal, must be certainly condemned for most purposes.

In order to avoid these inconveniences the following means are in the hands of the operator :

1. The compressing of the liquid steel after casting in order to obtain sound ingots.

2. Hammering the ingots before the rolling of them. 3. Heating the ingots to a mild welding heat.

Compressing of the steel in liquid state must be effectual, but as the hydraulic press used for this purpose is very expensive, the ordinary prices of Bessemer steel, worked in such a manner, must be to a certain extent increased. Next the maintenance of the press, requiring a powerful engine and a couple of boilers, is also dear.

The hammering of the ingots before the rolling of them is cheap, and the work may be done in the Bessemer shop immediately after casting if a steam_hammer may be placed in or near the casting house. The work requires a small amount of time, and the ingots, liberated from their moulds in 8 to 20 minutes after the casting of them, may be hammered, without placing them for this purpose into a furnace. After such an operation the surface blowholes are smoothened and have no action on the surface of plates; this has been remarked during several trials.

The process of welding the steel is the cheapest way of doing away with the surface defects. The metal superficially welds, and when rolled gives a plate with a clean surface. For this purpose gas furnaces or ordinary reheating furnaces with blast may be used. The ingot is covered with sand and remains in the furnace till the scale runs off. Next it is rolled as quickly as possible. This method is even cheaper than the ordinary way of heating the ingots in furnaces without blast to a white non-welding heat. Certainly great care must be taken not to overheat the ingots, and a clever man must look after the furnace. The burning of the carbon out of the metal is trifling during the heating of the ingot (1 to 2 hours), as show the following analyses of plates worked by this method :Per cent of Carbon.

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this pressure, without continual blowing, until it expends itself by expelling liquid from the jet.

2. The disagreeable reflux of steam into the mouth when washing with hot water, of ammonia or acid fumes when using solutions of either of the latter, can be completely prevented.

3. The flow of liquid from the tube A, when it is desired to use the bottle in that way, can be so accurately regulated by pressing the caoutchouc tubing that it is particularly valuable for diluting, filling measuring vessels, &c.

The jet I use, and which has been suggested by a friend, needs a word of explanation. It is bent, as shown, at F, and attached to the tube G, which dips into the liquid in the bottle, by a thick piece (thick enough to maintain

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the jet in position) of caoutchouc tubing, H, by turning which round G, the jet can be directed upwards, downwards, or sideways, as desired.

This wash-bottle can be used in every respect like the ordinary wash-bottle, and as conveniently, besides having the advantages described above. It has been used for the last nine or ten months by myself and others in the laboratory at Crewe, and has given every satisfaction. It is not at all liable to get out of order, and is but slightly more difficult to make than the ordinary form of bottle.

8, Martha Terrace, Henry Street, Crewe.

A NEW FORM OF WASH-BOTTLE. By M. H. FOYE.

In this wash-bottle the blow-tube consists of three parts -A, D, E (see sketch). A and E are pieces of glass tube. A passes through the stopper obliquely, outside the bottle, is bent at b, and terminates at c. E is bent as shown, and passes through the stopper to the interior of the bottle. D is a piece of caoutchouc tubing which stretches across the top of the stopper and connects A and E. Now it will be seen that by the action of the forefinger upon D, the blow-tube can be closed and opened at pleasure. The advantages of this arrangement are the following:

1. That after you create a pressure on the liquid in the bottle by blowing through the blow tube, you can, by compressing the caoutchouc tubing, maintain

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JOHNSON, in his investigation of potassium tri-iodide, noticed that on mixing strong solutions of potassium iodide and sulphurous acid, a yellow colour was produced, which was not bleached by more sulphurous acid, but disappeared on adding water. Gmelin ("Handbook of Chemistry," Watts, ii., 263) states, on the authority of Saladin (Fourn. Chim. Med., vii., 528), that hydriodic and sulphurous acids in aqueous solution form a yellow liquid, brighter in proportion to the concentration, and from which, eventually, sulphur is separated. Having myself verified this statement, I inferred that the yellow colour

20

Reactions of Iodine, &c., with Sulphurous Acid.

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given by potassium iodide with sulphurous acid was due
to the action of the latter upon the hydriodic acid set
free, and I was anxious to isolate the substance causing
the colour. That it could not be iodine was shown by its
resisting the action of excess of sulphurous acid, and by
its not colouring carbon disulphide. When the yellow
solution was shaken with ether, the latter was very slightly
coloured, but on adding a little alcohol and again shaking
the ethereal layer acquired a bright yellow colour, and
when drawn off and evaporated it left a brown oily sub-
stance, having a pungent odour somewhat resembling
that of bromine. On heating moderately it evolved
vapour of iodine. I made several attempts to obtain it in
a state fit for analysis, but the yield was always small,
and there was a tendency to the separation of plates of
iodine. I therefore tried to obtain it by the action of
sulphurous acid gas upon iodine dissolved in ordinary alco-
hol, hoping that, the quantity of water present being very
small, a larger quantity of the yellow substance would be
produced. One ounce of iodine was dissolved in 20 c.c.
of alcohol, and sulphurous acid was passed in to com-
plete saturation; the liquid remained of a dark brown
colour, which disappeared immediately on adding excess
of water. As it did not deposit anything after some days,
and was found to contain a little free iodine, small quan-
tities of water were added, and more sulphurous acid gas
was passed in until no more free iodine could be detected,
although the liquid had still a dark brown colour. On
standing it deposited a plastic substance resembling the
amorphous form of sulphur. This was freed by pressure
from adhering mother-liquor, when it weighed 0.140 grm.
On oxidising it with fuming nitric acid and precipitating
with barium chloride it gave barium sulphate corresponding
to 60 per cent of sulphur. Though disappointed in
isolating the substance, I submit that my experiments
justify the conclusion that the yellow body formed when
sulphurous acid acts upon concentrated solutions of potas-
sium and sodium iodide is an unstable iodide of sulphur, |
and I would suggest the following equations explaining
the reaction :-

(1.) KI+H2SO3=HI+KHSO3.

(2.) 8HI+2SO2=4H2O+16+I2S2 (?) (3.) 12+2H2O+ SO2=2HI+H2SO4. Chemical Laboratory, King's College, London.

NOTICES OF BOOKS.

A Treatise on Chemistry. By H. E. ROSCOE, F.R.S., and
C. SCHORLEMMER, F.R.S. Vol. II. Metals. Part I.

London: Macmillan and Co.

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tant processes as the manufactures of alkali and of bleaching-powder, are also described, if not so as to enter into every nicety, still in a manner which has in it no trace of the careless and the perfunctory. In these important respects the work is advantageously distinguished even as compared with such valuable treatises as those of Gmelin and Watt. Let any one, for instance, read the brief section on artificial soda in Gmelin (vol. iii., p. 79), and he will know how to appreciate the difference. Even some professedly technological works give less thorough descriptions of the various stages of the alkali manufacture than does the work before us. This feature is, we hold, of extreme value. Before the scientific chemist can bring his theoretical knowledge to bear usefully upon any of the industrial arts he should have an accurate general knowledge of their nature; of the various portions of the plant and of their functions, and of the difficulties which have been, or which still have to be overcome. Now, without wishing to convey the impression that mere reading can at once put the student in possession of practical knowledge, we hold that a young man fresh from college and entering upon the position of a "work's chemist," will find himself much sooner at home and do himself more credit if the work of Profs. Roscoe and Schorlemmer has been his guide than if he has merely been accustomed to manuals which scarcely condescend to refer to manufacturing operations. We believe that "theory with practice" is the key-word to industrial success, and in that conviction we congratulate the authors on their undertaking.

THIS is one of those books most valuable to the student, but the despair of the reviewer. We have no novel and questionable theories to criticise, no new facts of capital importance to point out. On the other hand, it will not be expected that the work of two chemists of such eminence can be rich in errors. We might, indeed, on careful examination come upon statements which we should hesitate to endorse. We may here and there think that some piece of information which has been omitted ought to have been given, and it would certainly be no difficult matter to select from the pages before us interesting facts not to be met with in those chemical hand-books, manuals, and treatises which have lately become somewhat too numerous. The book has, indeed, a distinctive character. Its illustrations, in their number, excellence, and accuracy, have few rivals. They are, further, not restricted to sketches of the apparatus used in the scientific laboratory or at the lecture-table, but include careful representations of the furnaces and other plant as now actually used in the best-arranged chemical manufactories and metallurgical establishments, with the additional recommendation of being drawn to scale. Such impor

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Coal, its History and Uses. By Professors GREEN,

MIALL, THORPE, RUCKER, and MARSHALL, of the
Yorkshire College. Edited by Prof. THORPE. London:
Macmillan and Co. 1878.

TowARDS the close of the year 1877 it was suggested to
the Professors of the Yorkshire College that by delivering
a series of lectures in some of the larger towns of the
West Riding they might aid in the good work which is
being done by Dr. Gilchrist's educational bequest. Each
lecturer was fain to choose his own topic, the whole of
them agreeing that, considering the locality in which they
were to lecture, they could not select a better general
subject than coal. Early in 1878, therefore, a series of ten
lectures was delivered in Leeds and Keighley in the fol-
lowing order: Lectures I. and II., on the Geology of
Coal, by Prof. Green; III. and IV., on Coal Plants and
Animals, by Prof. Miall; V. and VI., on the Chemistry of
Coal, by Prof. Thorpe; VII. and VIII., on Coal as a
Source of Warmth and Power, by Prof. Rücker; and IX.
and X., by Prof. Marshall, on the Coal Question. The
present volume consists of these ten lectures altered in
form, revised and arranged consecutively in ten chapters.
The only ones affecting our readers are those of Prof.
Thorpe, who has managed to introduce a certain amount
of fresh detail into this most hackneyed subject by giving
a popular account of Mr. J. W. Thomas's researches on
the gases occluded in coal. He also gives an interesting
description of the successive steps in the invention of the
Davy lamp, illustrated by diagrams. Mr. Ansell's fire-
damp alarm is also fully described and illustrated. The
lectures are illustrated with nearly sixty well-executed
A full index is appended.

cuts.

Year-Book of Pharmacy. Comprising Abstracts of Papers

relating to Pharmacy, Materia Medica, and Chemistry, contributed to British and Foreign Journals from July 1, 1877, to June 30, 1878, with the Transactions of the British Pharmaceutical Conference at the 15th Annual Meeting. London: J. and A. Churchill, 1878. THE ninth volume of the "Year-Book of Pharmacy," as usual, has appeared somewhat late. The book contains abstracts of papers relating to pharmacy contributed to British and foreign journals for the year ending June 30,

1878, and the Proceedings of the British Pharmaceutical Conference which held their sittings in the middle of August. According to the statement which Prof. Attfield made at the meeting held on August 12th, the MS. of the book was to have been laid upon the table on the following day; we cannot, therefore, understand why so long a period as three months and a half should be allowed to elapse before the appearance of the book, even supposing that the Transactions of the Conference were not included in the MS. mentioned by Prof. Attfield. The first part of the work is, as usual, particularly copious and complete, and gives us all the information contained in the principal pharmaceutical and medical journals issued in England and America during the period referred to in a condensed form.

I miligramme, and from I grain to 1000 grains. The thermometrical tables range from 260° C., 208' R., and 500°F., down to − 10° C., −1o R., and +14 F. The barometrical tables range from 27 inches to 30.98 inches. Boiling points, specific gravities, vapour densities, and solubilities follow. The tables showing the specific gravities of solutions of salts, &c., of different strengths, are particularly copious, but we cannot understand why it is that the temperature at which the specific gravities have been taken differ in every instance. The analytical tables are also very full. The pages on chemical manipulation might, we think, have been omitted. The glossary of minerals, giving their names, formulæ, hardness, specific gravity, and crystalline system, will render Mr. Bayley's little book indispensable to the mineralogist. We have throughout tested Mr. Bayley's vade mecum for tables of every sort and kind, and have every one down even to a ready-reckoner and wages table. The 421 pages which the book contains literally team with information, and we think it will puzzle Mr. Bailey to add very much to his second edition, which cannot fail to appear very speedily. The type in which the tables are printed is clear, though necessarily small in cases where much matter is crowded together, and there appear to be but few misprints.

expressed.

SOURCES.

The second part of the work, containing the Proceedings of the Conference, shows that the working members of that body have applied the wholesome lesson read to them by Prof. Attfield at the 1877 meeting, and we are glad to see that every paper, without exception, is of a thoroughly practical character from the pharmacist's point of view. The place of honour is occupied by the paper of Dr. Alder Wright and Mr. A. P. Luff, on the aconite alkaloids. Those improved processes for purifying the aconite bases have led to unexpected results. Thus, the substance described by them last year under the name of pseudaconitine is not a definite base, but a mixture of pseudaconitine and apopseudaconi- CHEMICAL NOTICES FROM FOREIGN tine, the latter being a dehydrated derivative of the former. The substance again which was last year regarded as pseudaconine is now distinguished as apopseudaconine, and is a dehydrated derivative of true pseudaconine. NOTE.-All degrees of temperature are Centigrade, unless otherwis True aconitine also forms a similar series of dehydrated derivatives. The veratrum alkaloids seem likely to afford a similar series of bases. The alkaloid or alkaloids obtained from aconitum ferox are still a puzzle. In any case they appear to differ both from aconitine and pseudaconitine. The outcome of all these apparently recondite researches is of the highest possible practical importance, Hitherto the pharmacist has been unable to present the physician with any preparation of either British or foreign aconite root which had a constant composition, but now, as the result of the investigations of Dr. Wright and his colleagues, the active principle of the drug will be procurable in a form whose composition will be nearly as definite as that of potassium nitrate. Mr. Shenstone's researches on the action of nitric acid on strychnine seem to disprove Prof. Sonnenschein's alleged discovery of the formation of brucine by this method, and would also lead us to suppose that pure brucine has not yet been procured. Most of the other papers are of too technical a nature for notice in our pages.

A Pocket-book for Chemists, Chemical Manufacturers,
Metallurgists, Dyers, Distillers, &c. By THOMAS
BAYLEY, ASSOC. R.C.Sc.I., Demonstrator of Practical
Chemistry, &c., in the Mining School, Bristol.
London: Spon and Co. 1878.

A HANDY little book that has long been wanted, and of
whose usefulness it would be needless to say anything.
Hitherto chemists have been obliged to fall back on the
very incomplete little note-book of Gutch or the French
Addenda of Dunod, and it seems surprising that the want
has never been supplied. The tables, of course, begin
with a list of the elements, their symbols, atomicities.
and atomic weights; but why, we may ask, are the latter
repeated twice? once according to the latest determina-
tions, and again according to some obsolete table. The
space thus wasted might have been devoted to the date
of the discovery of the newer elements and the names of
their discoverers. Various other tables, data, and formulæ
follow, one of the most useful being a table of coefficients
giving the amount of the constituent sought by simple
multiplication. Another is a table for the conversion of
grammes into grains and vice versa, from 1000 grammes to

Comptes Rendus Hebdomadaires des Séances, l'Académic de des Sciences. No. 24, December 9, 1878. Artificial Pyroxene (Diopside).-L. Gruner.-Crystals of this mineral have been obtained from bricks very rich in lime and magnesia, after being exposed for some time to an intense heat ir. a furnace.

Influence of Atmospheric Electricity upon the Fructification of Plants.-L. Grandeau.-Atmospheric electricity in two sets of experiments conducted at Nancy and at Mettray decidedly promotes fructification.

Disease of the Coffee-tree Observed in Brazil.

C. Jobert.-This affection, the symptoms of which are minutely described, attacks chiefly plantations in moist and shady situations, and appears to be caused by Anguillula which attack the roots.

Diffusion of Heat by Leaves.-M. Maquenne.-The green organs of plants diffuse a considerable proportion of the heat-rays which they receive, this action being almost always accompanied by imperfect reflection, the reflected rays being polarised in the plane of incidence. The proportion of rays diffused in the case of normal incidence diminishes with the temperature of the source of heat.

The Power of Kinds of Wood in Absorbing Water. -E. J. Maumené.-The author finds the proportion of water absorbed by different sorts of wood varies from 9'37 to 174.86 per cent.

No. 25, December 16, 1878.

Observations on M. Pasteur's Paper on Alcoholic Fermentation.-M. Berthelot.-The author, feeling himself reflected upon by M. Pasteur's remarks on the posthumous essays of Claude Bernard, has undertaken a novel and interesting experiment. He writes, "when speaking of a soluble alcoholic ferment capable of being consumed step by step with its production and in the very chemical act which it determines, I took care to add that, for the demonstration of this hypothesis, it would be necessary to discover the conditions in which this ferment is produced in more considerable proportions than the quantity destroyed in fermentation. Such were the con

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