pointed out the fact that mercurial ointment contains a portion of the mercury in chemical combination dissolved in the fat. He suggested that the efficacy of the ointment might be mainly due to this compound, and showed that if this be the case a more elegant ointment could be prepared by digesting black oxide of mercury in melted lard for some time, and then filtering. A solution of some of the oxide is thus effected, but the amount taken up is not large, and the ointment so made did not come into use. Professor Marshall is now employing a solution of the red oxide of mercury in oleic acid as a substitute for mercurial ointment. A definite compound, the mercuric oleate, is thus formed, which can be so made that it shall contain 20 per cent. of the metallic oxide. The yellow mercuric oxide obtained by precipitation combines with the oleic acid, when digested at a moderate heat, forming a white unctuous substance of elegant appearance. Three strengths of the preparation are used, containing respectively twenty, ten, and five per cent. of oxide of mercury. They are also employed in association with the oleate of morphia, which is similarly prepared by combining the pure alkaloid with oleic acid. The oleate of mercury and morphia, however, appears to undergo some change by keeping, and acquires a dark colour.

Nearly ten years ago Professor Attfield, in a paper on a method for dissolving alkaloids in oils, directed attention to the fact that oleic acid readily combines, not only with the organic alkaloids, but also with the oxides of lead, mercury, zinc, and iron, yielding compounds which are freely miscible with oils and fats, and well adapted therefore for use in ointments or liniments.

Oleic acid can now be obtained in commerce in considerable quantities, and at a very moderate price. It is possible, therefore, that it may find other applications in pharmacy, more especially in the preparation of a pure potash soap, which would advantageously replace the present Sapo Mollis of the Pharmacopoeia.

M. G. Tissandier has pointed out a reaction by which pure anhydrous ferrous oxide in a stable condition may be obtained, which may possibly prove useful in pharmacy. It is known that when carbonic acid gas is passed over red-hot iron, it is reduced to carbonic oxide. M. Tissandier shows that the oxide of iron formed is the pure protoxide. Coils of clean iron wire are heated to redness in a porcelain tube through which pure dry carbonic acid gas is passing. When the wire is afterwards taken out, scales of protoxide may be removed from its surface, in the form of a black, brilliant, and crystalline substance.

Sulphovinate of sodium has been used by several French physisicians as a saline purgative with very favourable results. It is said to possess a slightly sweetish taste, and to be an efficient purge in adult doses of 20 grammes, without inducing any subsequent constipation. In smaller doses it is given to children, either mixed with a fruit syrup or in effervescing waters. M. Limousin has given details of the process by which it may be economically prepared, and states that when well crystallised and thoroughly dried it may be kept exposed to the air without undergoing any alteration.

The bromine derivative of camphor has lately been employed in Brussels and also in America as a sedative to the nervous system. This body is formed by the action of, bromine on camphor. It crystallises in colourless needles, and has the composition C20 His Br O2. It is given in does of two to five grains, and has been favourably reported on by Dr. Hammond in New York. Prof. Maisch has given full details of its preparation and properties.

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Chloral seems to have definitely taken its place as a permanent article of the materia medica. It is now met with in commerce in a sufficient state of purity. It is true that samples are sometimes met with which are very pungent, and after being kept for a while emit au acid vapour on opening the bottle; but this seems to arise not so much from any foreign body left in the product by its manufacture, as from a slight deficiency of the water of hydration, the trace of free chloral probably undergoing some decomposition. Certainly the chief difficulty in the preparation of the hydrate is to obtain it with the exact amount of water necessary; a slight excess causing an appearance of deliquescence, while any deficiency leads to the pungency, which is, if anything, more objectionable. Dr. Squibb, who last year gave some valuable details of the method of manufacture, has this year given us the results of his experience on the best means of testing the quality of the product. He, in common with others, rejects the chloroform tests as of little value, and looks rather to the detection of secondary products which may remain as impurities from imperfect manufacture.

The crotonic chloral, first obtained by the action of chlorine on aldehyde (see Year Book, 1871, p. 242), has been found to possess valuable therapeutical properties, distinct from those of ordinary chloral. It has been administered in cases of insanity with peculiar benefit, and from its specific power of narcotising the fifth part of cerebral nerves, it is likely to prove a useful remedy in neuralgia. It has been given in doses of 5 to 10 grains.

MM. Wurtz and Vogt have investigated the theory of the forma

tion of chloral, and from their results it appears that the change is not so simple as it has been generally represented. The first step leads to the formation of some aldehyde; this fixes the elements of ethyl-chloride, produced at the same time, forming a compound which by the action of chlorine furnishes a tetrachlorinated body, C, H, Cl, O, already known as obtained in other ways by Malaguti and also by Henry. This tetrachlorinated ether, treated with water, gives chloral according to the equation

6

C. H. Cl O + H2O = C, H Cl, O + C2 H¿ O + H Cl.

2

6

The necessary water is supplied by the reaction of the hydrochloric acid which has been generated upon the aldehyd and alcohol.

M. Byasson, who has published some researches on the physiological action of hydrate of chloral, has also obtained a body in which the water of hydrate of chloral is replaced by sulphuretted hydrogen. This sulphydrate, C, H Cl, O. H, S, is a crystalline body which is decomposed by water. It is easily produced by passing dry sulphuretted hydrogen through anhydrous chloral.

In like manner, C. Bischoff and A. Pinner have obtained a crystallised cyanhydrate, C, H Cl, O. C N H, the water of the hydrate being replaced by hydrocyanic acid. This body, when digested with strong hydrochloric acid, is split up, yielding ammonium chloride and trichlorolactic acid. C. Bischoff has also obtained a combination of chloral with cyanic acid, in which two molecules of chloral are associated with one of cyanic acid.

Trichloracetic acid has been sometimes recommended as a caustic

-more especially as a solvent for warts and corns. It may now be readily produced by the action of nitric acid on chloral hydrate. M. Clermont has given the details of the process, and has also described some of the trichloracetates.

Disinfecting agents still continue to receive a great deal of attention. A commission appointed by the French Academy of Sciences have assigned the first place to hyponitrous acid as a gaseous disinfectant. They recommend a vessel containing copper turnings and diluted nitric acid to be placed in any apartment where contagion is feared, the room being then closed as perfectly as possible for 48 hours. Sulphur is frequently employed for destroying the parasites infesting plants and animals. Mr. C. Roberts considers that its efficacy in such cases depends on the presence of sulphurous acid. It is well known that ordinary flowers of sulphur possess a distinctly acid reaction, which may be removed by washing, and Mr. Roberts shows that washed sulphur is inert. He also shows that sulphur

is capable, like charcoal, of absorbing a large quantity of sulphurous acid gas. He proposes to employ sulphur, thus artificially charged, for horticultural purposes; under the name of sulphozone. Last year we directed attention to some considerable improvements in the preparation of pepsin. A further contribution to this subject has been made in a valuable paper by E. Scheffer, containing a very practicable method for extracting pepsin in a convenient form for medicinal use. The process is based upon the insolubility of pepsin in a strong solution of chloride of sodium. A cold acidulated infusion of the mucous membrane of pigs' stomachs is prepared, which is mixed with a saturated solution of common salt, when the pepsin is precipitated, and may be collected on a cloth, and pressed. It may either be allowed to dry by exposure to the air, or rubbed with sugar of milk to a fine powder. The quantity of the latter is so adjusted that 10 grains of the product will dissolve 120 grains of coagulated albumen.

An interesting fact pointed out by Mr. Scheffer is that the albumen, which has been dissolved by pepsin, itself acquires peptic properties, and will dissolve further quantities of coagulated albumen. In this way, with half a grain of pepsin, he succeeded in ultimately obtaining 1500 grains of coagulated albumen into solution. Moreover, by the addition of common salt solution to the liquid so formed, a precipitate was obtained, which he named pepton, and which possesses remarkable digestive powers.

Mr. R. V. Tuson, the Professor of Chemistry at the Royal Veterinary College, has written a preliminary note on the investigation of a subject possessing considerable interest to the physiologist. He is engaged in studying the action of digestive fluids on those mineral substances which are used in medicine. He finds that while pepsin alone and hydrochloric acid alone are incapable of acting on calomel, a solution of acidified pepsin, when digested at the temperature of the body with pure mercurous chloride, is capable of taking a portion of the mercury into solution.

G. Vulpius has also described experiments in some of which calomel was digested with pepsin, where somewhat different results were obtained. He finds that under certain circumstances pepsin is capable of removing mercury from solution.

Although ipecacuanha wine has been for a long time considered in several respects an unsatisfactory preparation, it still remains the only liquid preparation of the drug in very general use. Some years ago, Mr. G. Johnson proved that the presence of an acid in the fluid menstruum is necessary to retain the active constituent of

ipecacuanha in permanent solution. Dr. Dyce Duckworth has been engaged in studying the therapeutical action of this drug, and in a recent paper has expressed himself dissatisfied with the officinal wine. He recommends as preferable preparations an acetum and an oxymel, formulæ for which have been arranged by Mr. Carteighe. The variability sometimes observed in the activity of cantharides plaster is discussed by Professor G. Dragendorff, who considers that it is not so much due to the poorness of the flies used, as it is to the difficulty of thoroughly extracting the cantharidin they contain. He finds that the poorest flies will yield an active plaster, if they are first moistened with solution of potash, and, after digestion, neutralized with hydrochloric acid, and dried. Mr. R. Rother, who has also worked at the same subject, prefers damping the powdered flies with turpentine or chloroform, whereby the cantharidin is rendered more soluble in the fatty basis.

Dr. Squibb finds the best vesicating preparation to be a fluid extract prepared with a mixture of liq. potassæ and alcohol by percolation. Massing and Dragendorff have shown that cantharidin may be viewed as the anhydride of an acid; and that by treatment with alkalies, it is capable of being converted into cantharidates; and Delpech and Guichard have proposed to use the cantharidate of potassium as a vesicating agent. Dr. Squibb's extract probably contains this salt, and in addition the oil of the fly, which he states also possesses independent vesicating properties.

From the researches of Professor Flückiger and Dr. Tilden, our knowledge of the composition of aloes, and the constitution of the crystalline principle, aloin, has been considerably increased. The nataloin discovered by Professor Flückiger in the aloes from Natal has been examined by Dr. Tilden with interesting results. Some years ago, Hlasiwetz showed that Socotrine aloes yield, by treatment with caustic potash, paraoxybenzoic acid and a orcin (C, H, O2). Dr. Tilden finds that nataloin yields, by similar treatment, paraoxybenzoic acid and 8 orcin (C, H, O2) or some higher homologue of that body. He has moreover obtained from nataloin the acetyl derivative C25 H (C2 H3 O) 011

22

10

In conjunction with Mr. G. Rammel, he has further investigated the nature of the so-called resin of aloes; that is to say, the resinous looking body which remains insoluble in the preparation of the aqueous extract of aloes. By repeated treatment with boiling water they succeeded in resolving this substance into two portions, one of which was soluble in hot water, the other insoluble. Their analysis and experiments point to the conclusion that the first of these pro