[MAY, similar to tallow, the other to wax. By evaporating the liquid a considerable quantity of oxalic acid in crystals was obtained. The mother water still contained oxalic acid, and a portion of the bitter principle from indigo.

When fungin is steeped in an infusion of nutgalls, it imbibes a considerable portion of the tannin, and acquires a fawn colour. When left to putrefy spontaneously in water, it emitted first the odour of putrefying gluten, then that of putrid meat. Neither acid nor ammonia was found in the water; but it contained a portion of mucilage, which gave it viscocity, and the property of precipitating with acetate of lead. The fungin itself assumed the aspect of gluten, without however possessing its properties. IV. Extract of a Letter from Dr. John Redman Coxe, Professor of Chemistry at Philadelphia. Dated August 1, 1812.

I beg leave to mention to you, that authors have generally considered that muriatic acid and alcohol have little action on each other, except through some complex affinities, which it will be unnecessary to state. I have, however, discovered that time is an agent of some importance in producing an union, and à consequent formation of ether. In 1809-10 I had mixed equal parts of those substances (in a vial) of the common standards, and had left them corked, occasionally opening the vial, to ascertain what change ensued. For several months the muriatic smell predominated, and I was led to conclude no change would occur; in consequence of which, I laid aside the vial, and did not think of it for upwards of a year: on accidentally looking for something else, I found the vial; and on opening it, was surprised to find a strong ethereal smell, which still continues, although I have frequently since opened the bottle. The muriatic smell is gone; and I mean to try if distillation will not extricate an ethereal fluid. I leave it, however, until winter, in hopes of being more certain than during the hot weather. Not anticipating such a result, the quantities are but small, and of course less likely to evolve much, if any. As the fact may be new to you, I thought it might be acceptable, as it evinces that certain actions may not ensue, until after the expiration of a considerable period.

Another fact I shall call your attention to, is the presumed necessity of atmospheric pressure in certain cases of crystallization. You well know the common explanation of a saturated solution of sulphate of soda tied up warm, and remaining fluid until the bottle is opened, or exposed to such pressure. It is evident, however, that some other explanation must be sought for, since I have ascertained, by repeated trials, that the bottle thus prepared may be set aside uncorked, exposed to the full action of the air, and that it will nevertheless remain perfectly

fluid, even if taken up with care, and solidification does not ensue until agitation takes place. I had made a solution of this salt in a large vial to the full extent that the water could take up by exposure to an almost naked fire. At this time I was obliged to leave it, and neglected to cork it, fully expecting the next day to find it completely solid. It was, however, perfectly fluid; but solidified almost instantly on my taking it from the table. Since that period I have annually exhibited to my Class bottles equally strong in solution, some corked, and others uncorked, and both remaining fluid at the end of 24 hours, and becoming solid by the usual means of agitation after the cover of the former was penetrated, and by shaking the latter. I have also found occasionally bottles thus prepared and corked, solidified where I had no reason to expect it; and frequently I have seen a part of the salt reduced to a solid form in a close bottle, and when opened and shaken the whole becoming solid, with a singular change in the appearance of that part of the salt which had been previously precipitated. It assumed, whilst the latter precipitation or formation of crystals was going on, a very beautiful porcellanous white appearanee, which remained permanent at the bottom of the last formed crystalline mass, and I have now some in that state thus produced during the last winter. has occurred so frequently, that I cannot consider it accidental; but I am at a loss to explain the fact. From mere appearance I ⚫ should conclude the salt thus previously produced had entirely given up its water of crystallization. That something more than mere atmospheric pressure is necessary, however, to explain the common occurrence cannot, I think, be denied. I shall be glad to find it succeed in your hands, and to have your opinion respecting it. If the common explanation was correct, why can we not effect the same with nitrate of potash? I have repeatedly tried, but ineffectually.

It

I have several times, since I wrote to you last, tried the reforming of pyrophorus, by adding a portion of solution of potash to imperfect pyrophorus, and exposing to heat, with complete success. I have, therefore, little doubt of the whole phenomena being dependant on the formation of a portion of potassium spread through the mass, and inflaming through the instrumentality of atmospheric moisture, &c. I have even once tried it successfully on pyrophorus already ignited by exposure to the air; and hence it may be useful to preserve that which has undergone the change, till a sufficient quantity is obtained to be again treated with the addition of potash, since it wilk save the trouble of the preliminary steps, and we have at hand the materials in a very dry and perfect state for the process.

V. Use of Magnesia in Calculous Diseases.

The Editor is requested by Dr. Henry to state, that he never

made the least claim to the suggestion of the trial of magnesia in calculous diseases (erroneously ascribed to him in a recent and valuable work of Professor Berzelius on animal chemistry), and that the merit of the hint, which led to the successful experiments of Mr. Brande, belongs entirely to Mr. Hatchett.

VI. Fepper.

There is a very singular fraud which has been practised for some time past in some of the retail shops in London. Artificial pepper-corns, both white and black, are mixed with real peppercorns, and this fraudulent mixture sold as genuine pepper. The mode of detecting the cheat is easy. Throw a handful of the suspected pepper-corns into water: the artificial corns fall to powder, or are partially dissolved; while the true pepper-corns remain whole. I am told that these fraudulent pepper-corns are made of peasmeal. The fraud should be publicly known, because such a mixture, if used instead of real pepper, may prove, in many cases of household economy, exceedingly prejudicial to those who ignorantly make use of it.

ARTICLE X.

Proceedings of Philosophical Societies.

ROYAL SOCIETY.

ON the 1st of March some additional observations on the tusks of the narwal, by Sir Everard Home, Bart. were read. He found in the skull of a female narwal two milk tusks, about nine inches long. Hence that animal, when fuli grown, would have had tusks. On sawing in two the tusk of a narwal it was found mostly hollow. This is the reason why it cannot be used, like ivory, for the purposes of art.

At the same meeting of the Society, a paper by Dr. Wells was read, giving an account of a woman, the offspring of white parents, part of whose skin was black. The name of the woman is Harriet West. She was born in Suffolk, about eight miles from the sea coast; and she is at present about 23 years of age. Her father was a footman, and died when she was very young. She is the only child of her father; but her mother, who was married a second time, has had 11 children since, all white. Her mother, when pregnant with her, got a fright by trampling on a live lobster; and to this the spots on her skin were ascribed, The whole of her body is very white, except the right shoulder, arm, and hand, which are mostly black, except a white stripe on the fore arm. The black parts are darker than in a negro. Winslow has observed, that the cuticle in negroes is black; and

Dr. Wells found this the case with the black cuticle of Harriet West. From this curious case, Dr. Wells draws the following inferences:-1. The black colour of negroes does not prove them to be a distinct race of animals from the whites. 2. The black colour cannot be ascribed to the action of the sun merely, as is the common opinion. An additional proof of the fallacy of such an opinion is, that those parts of negroes which are exposed to the sun are not so black as those that are covered with clothes.

On Thursday the 8th of March Dr. Wells's paper was concluded. He gave his opinion about what occasioned the difference between negroes and whites. It is well known that whites are not so well able to bear a warm climate as negroes; and that they are liable to many diseases in such a situation, from which negroes are free. On the other hand, whites are much better fitted to bear a cold climate than negroes: Suppose a colony of whites transported to the torrid zone, and obliged to subsist by their labour, it is obvious that a great proportion of them would speedily be destroyed by the climate, and the colony, in no long period of time, annihilated. The same thing would happen to a colony of negroes transported to a cold climate. Dr. Wells conceives that the black colour of negroes is not the cause of their being better able to bear a warm climate, but merely the sign of some difference in constitution, which makes them able to bear such a climate. Suppose a colony of white men carried to the torrid zone; some would be better able to resist the climate than others. Such families would thrive, while the others decayed. These families would exhibit the sign of such a constitution; that is, they would be dark: and as the darker they were, the better they would be able to resist the climate; it is obvious that the darker varieties would be the most thriving, and that the colony, on that account, would become gradually darker and darker coloured till they degenerated into negroes. The contrary would happen to negroes transported to cold climates.

Dr. Wells conceives that the woolly hair, and deformed features, of the negroes, are connected with want of intellect. The negroes have been always slaves; and there is no instance of their better shaped neighbours being subject to the negroes.

The same evening a paper by I. Berzelius and Dr. Marcet, on the alcohol of sulphur, was begun. This substance was discovered several years ago by Lampadius, while distilling a mixture of charcoal and pyrites. He called it alcohol of sulphur from its great volatility. He conceived it to be a compound of sulphur and hydrogen. Clement and Desormes obtained it soon after by passing sulphur through red-hot charcoal; and from their analysis it appeared to be a compound of sulphur and charcoal.

Berthollet, in his elaborate remarks upon carbonic oxide, and his critique upon the experiments of Clement and Desormes, revived the opinion of Lampadius; and this was confirmed by the experiments of Berthollet, jun. The subject was lately resumed by Clusel, who concluded from his experiments, that the substance was a triple compound of sulphur, charcoal, hydrogen, and azote. Thenard examined the substance anew, and found it a compound of sulphur and charcoal alone. These discordant results prevent any confidence from being put in the various experiments already made. It was to remove the doubts still hanging over the subject that Berzelius and Marcet were induced to undertake the investigation of the subject.

LINNEAN SOCIETY.

On the 6th of April the remainder of Mr. Keith's paper on the cotyledons of grasses was read. He found by examination that the sheath of the plumula never assumes the form of a true leaf; that it rises out of the ground, is at first white and transparent, and then becomes purple; and that it divides, and allows the leaf of the plumula to pass through it. The secondary shoots are also furnished with sheaths; but their structure is quite different from that of the plumula. As to the scale called vitellus by Gærtner, Mr. Keith conceives that it may be intended to act as a strainer to the milky food prepared in the albumen.

At the same meeting an analysis of arragonite, by the Rev. John Holme, of St. Peter's College, Cambridge, was read. This mineral has been long known to mineralogists, and constitutes an anomaly in the Haiyan theory of crystallization. The figure of its crystals, its specific gravity, its hardness and lustre, differ from the same properties in calcareous spar; yet its constituents, as far as chemical analysis has gone, are absolutely the same. It has been analysed by Klaproth, Bucholz, Vauquelin, Chenevix, Thenard, and Biot; but nothing different from the constituents of calcareous spar was found. Mr. Holme conceives the difference to depend upon a quantity of water chemically combined in arragonite, while calcareous spar is destitute of that constituent. He found that when exposed to heat it gives out water without decrepitating, and at the same time falls to powder. This water was found to contain no carbonic acid gas, nor was any given out under a red heat. The constituents of arragonite, according to Mr. Holme, are as follows: