THE STATE IN WHICH BUTTER EXISTS IN MILK.

BY M. ROMANET.

THE author endeavours to establish the following propositions, in reference to the phenomena attending the formation of butter:

1st. At the moment of the emission of the milk, the globules, of various dimensions, which are clearly discerned by means of a microscope, and which tend, by reason of their specific gravity, to rise to the surface, contain the butter in a perfect state.

2d. These globules contain the whole of the butter, and nothing but butter. 3d. This substance is found in the form of a pulp, enveloped in a pellicle, which is white, translucent, thin, elastic, and resistant.

4th. The action of churning produces no other effect than by constant rubbing, to attenuate the pellicles which envelope the pulp, and ultimately to cause their mechanical rupture, thus setting at liberty the butter.

5th. If the butter is all formed almost at the same instant, after the churning has been continued for a certain period, it is because this mechanical action is exercised pretty equally upon all the globules within the same space of time, so that the rupture of the pellicles takes place nearly simultaneously. 6th. It is the empty coats of the globules which render the butter-milk and the water employed to wash the butter, white and opaque.

7th. The acidity which is always manifested in butter-milk, at the instant of the formation of the butter, however fresh and alkaline the cream might have been when put into the churn, is due to the immediate contact of the butter, and the acid principles which M. Chevreul has shown to be contained in this substance; a contact from which the liquid was preserved while the particles of butter were retained in their envelopes."-Comptes Rendus de l'Académie des Sciences.

PURE BORACIC ACID.

THE usual method of preparing boracic acid consists in decomposing borax by means of sulphuric acid; but the boracic acid thus obtained is always contaminated with a certain quantity of the sulphuric acid used in its preparation. M. Wackenroder has pointed out a better method, as follows: dissolve forty parts of borax in one hundred parts of boiling water, and add twenty-five parts of hydrochloric acid to the solution while hot. Collect, on a filter, the boracic acid, which will crystallize on the cooling of the liquor, wash it a few times with cold water, allow it to drain, redissolve it in a little hot water, and crystallize it a second time. Wash the crystals with a little cold water and press them between folds of filtering paper. The mother-water and the washings of the crystals may be evaporated so as to afford a further quantity of the acid. This boracic acid, when dry, will still retain a trace of free hydrochloric acid which may be driven off with a part of the water of crystallization by drying the acid at a temperature of about 234° Fah. After this operation the acid is pure.-Berselius's Report on the Progress of Science.

MEDICINAL PHOSPHORIC ACID.

M. VAKENRODER finds that medicinal phosphoric acid is best prepared by a process already known, but which he has modified in the proportions of the ingredients, and also in the manipulation. The following is his process: mix 200 parts of calcined bones, reduced to fine powder, with 1300 parts of water; add to them 150 parts of sulphuric acid diluted with 200 parts of water; after allowing them to remain in contact, in the cold, for twelve

hours, expose the mixture to the action of a gentle heat for half an hour, replacing the water which is lost by evaporation. The liquor is now to be strained off with expression, and the mare washed with 200 parts of water. Filter the solution, and pass a stream of sulphuretted hydrogen through it; filter it again, and then evaporate it down to 160 parts; add to it 320 parts of alcohol; after twenty-four hours filter the solution, and wash the filter with thirty parts more of alcohol. Recover the alcohol by distillation, and evaporate the residue until reduced to 36 parts; add distilled water to make it up to 120 parts; digest it with charcoal, filter, and concentrate the acid. Phosphoric acid thus prepared, still contains a little superphosphate of lime, but it is sufficiently pure for medicinal use.-Soubeiran's Pharmaceu tical Notes.

PROCESS FOR OBTAINING BENZOIC ACID

VERY PURE, AND FREE FROM EMPYREUMATIC SMELL.

BY M. JAUSSENS.

Mix one part of benzoic acid of commerce with eight parts of distilled water, add an excess of solution of ammonia, and afterwards treat the solution of benzoate of ammonia formed, with purified animal charcoal.

Filter the solution, and decompose it with hydrochloric acid; the benzoic acid will be separated in the form of beautifully white flakes. These flakes, thrown on to a filter and washed several times with distilled water, are afterwards to be drained, and then dissolved in a sufficient quantity of alcohol. The alcoholic solution is to be filtered, and then diluted with distilled water, so as to precipitate the benzoic acid, which is but sparingly soluble in this liquid. By this means, the essential oil, to the presence of which in the ordinary flowers of benzoin their peculiar smell is due, is retained in solution in the alcoholic liquor. It only remains to crystallize or sublime the precipitated acid to obtain it in a state of great purity and beauty.-Archives de la Médicine Belge.

PROPERTY POSSESSED BY CERTAIN SPECIES OF SUGAR AND OTHER NEUTRAL VEGETABLE PRINCIPLES,

TO DISSOLVE SOME OF THE METALLIC OXIDES IN COMBINATION WITH THE ALKALIES.

BY M. LASSAIGNE.

THE author at the conclusion of a memoir presented to the Academy of Sciences at Paris, gives the following as deductions from the facts adduced: 1st. A certain number of immediate neutral principles obtained from vegetables, such as the different kinds of sugar, possess the property of rendering soluble in water, by the aid of the alkalies, several hydrated metallic oxides.

2d. Many of the resulting compounds are similar in colour to the solutions of the salts of these oxides.

3d. These soluble compounds may be compared to double salts, in which the organic matter plays the part of an acid.

4th. Among these compounds, those which have for their base the deutoxide of copper, are either spontaneously, or by the direct application of heat, destroyed. In this reaction, the deutoxide of copper is reduced to the state of protexide, which separates either combined with water, or in the anhydrous state, according to the concentration of the liquid. - Comptes Rendus.

PROCESS FOR THE PREPARATION OF ULTRAMARINE.

BY M. J. DE TIREMON.

TAKE OF

Fine clay, powdered and sifted

Gelatinous alumina, representing of the anhydrous
Carbonate of soda, dried, 400 parts, or crystallized
Flowers of sulphur
Sulphuret of arsenic

The mixture of these substances must be made with great care. Into the carbonate of soda, liquified with its water of crystallization, throw the sulphuret of arsenic in powder, and when this latter substance is partly decomposed, add the gelatinized alumina (this alumina is obtained from the alum of commerce, precipitated by carbonate of soda-the precipitate collected on a filter, and washed once with river water). Afterwards add the clay and the flowers of sulphur previously mixed. This mixture, reduced by the beat, is put into a covered crucible, carefully heated, to drive off the remaining water, then raised to a red heat. The fire should be so managed as to agglutinate, but not to melt the mass. After allowing it to cool, it must be again heated to drive off any remaining sulphur, it must then be broken and rubbed down with river-water. The powder held in suspension in the water is collected on a filter. When the mixture has been well made, the whole of the product may be used; but in case the combination has been imperfect, there will be found a number of colourless particles, or when the heat has been carried to complete fusion, there will be some fragments of a brown colour, especially when the crucible is of a bad quality, and has been much acted upon. These results never occur when the operation is conducted with care. The filter should be allowed to drop without further washing the powder, and the latter is then to be dried. The product will be of a beautiful soft green colour, which afterwards becomes blue.-Comptes Rendus.

BOOKS RECEIVED.

The Cyclopædia of Popular Medicine, intended for Domestic Use, with numerous Illustrations. By KEITH IMRAY, M.D. Simpkin, Marshall, & Co.

THE object of this work is, as the author states, "to describe in plain and simple terms the causes, symptoms, and treatment of disease-the whole science of medicine rests on these three points: we ascertain causes for the purpose of avoiding, symptoms for the purpose of distinguishing, and treatment for the purpose of curing, disease."

It is not the design of the author "to supersede the practice of medicine, by making every man his own doctor; but to afford simple rules for the alleviation of disease and the preservation of health, which may be had recourse to whenever circumstances render it expedient or necessary."

Some difference of opinion prevails as to the amount of medical

knowledge, which the public ought to possess. Danger sometimes arises from an undue confidence in a superficial acquaintance with this subject; and, on the other hand, fatal errors are not unfrequently the result of ignorance. In the present age, when education in all its branches is extending itself in every grade of society, the science of medicine is unquestionably entitled to a share of popular favour. There are certain facts relating to physiology and the functions of life, the effects of remedies in daily use, and the amount of importance to be attributed to ordinary symptoms, with which all persons should be more or less conversant.

The especial purpose for which this knowledge is essential, is in enabling patients to judge when it is necessary to send for a medical man. The want of it is a great source of perplexity from which much mischief arises. A person who is unacquainted with the liabilities indicated by certain symptoms, often loses the opportunity of obtaining timely advice, until a disorder has assumed a formidable aspect.

The work before us affords that kind of information which is likely to be useful. The early symptoms and usual course of various disorders are concisely described, and such remedies are enumerated as are likely in ordinary cases to afford relief. General rules respecting diet and regimen are introduced, and many of the evils to be apprehended in each particular case are pointed out. A variety of well selected formulæ are interspersed in the work, and it also contains plates illustrating the best modes of applying bandages to fractured limbs. This latter subject goes rather beyond what appears necessary for popular use, and is, as well as some other portions, more adapted to students in medicine or surgery than to the public in general.

Some precautions are always necessary in the application of a work of this description. Much injury may sometimes be done by scrupulously following instructions of a general nature, which may happen to be inapplicable to the particular case. It too often occurs that persons whose knowledge is superficial, are struck with some isolated fact or observation, and act upon it without considering other particulars, or understanding the principle on which the course is recommended.

In treating of asthma Dr. Imray observes, some individuals are much relieved by drinking brandy and water." We have no reason to doubt the fact, but would not recommend all asthmatic patients to adopt the beverage.

Again, the following injection is recommended as a remedy for Gonorrhoea :

"Nitrate of silver five grains.

Water one ounce. To be injected two or three times a day."

"Under urgent circumstances, it may sometimes be cut short by injecting the nitrate of silver (ten grains to the ounce) as soon as the pain and scalding are discovered."

This may be very good practice in the hands of the surgeon, but if adopted by patients who are unacquainted with the modus operandi of nitrate of silver, the remedy might prove worse than the disease.

Similar observations might be made with reference to the administration of elaterium, digitalis, strychnia, and inany other drugs of a powerful nature, which ought rarely, if ever, to be ventured upon by patients, in the absence of medical advice.

The remedies with which the public are entrusted, should be such as may be used without any particular risk, and which do not require a very minute observance of their effects from time to time, in order to regulate their continuance or the dose. But it is impossible to limit popular materia medica by any general rule, or to point out the boundary line of safety in this respect. There is indeed a limit, beyond which even the experience of the most skilful physician is unavailing, but this also is involved in mystery.

The great object in a popular work on medicine should be to describe, as explicitly as possible, not only the liabilities which accompany various forms of disease, but also those which belong to the treatment, and rather to instruct the patient when to apply for medical advice, than to induce him to undertake the treatment of himself, by giving directions which, however elaborate, can never supply the place of practical knowledge.

These precautionary remarks, with reference to patients, are equally applicable to Pharmaceutical Chemists, whose duty it is to use every possible precaution in the sale of powerful medicines, and to refuse to supply them when they have reason to apprehend that injury might result.

Manual of British Botany. By D. C. MACREight, M.D. John Churchill, Princes Street, Soho.

In this work, the plants indigenous to, and commonly cultivated in Great Britain, are arranged and described according to the natural system of De Candolle, and a series of analytical tables is given for the assistance of the student in the examination of British plants. It is principally intended as a book of reference, and has evidently been compiled with considerable care and labour.