quarter Dr. Berzelius has also given to the English reader a general view of the composition of animal fluids. A paper, submitted to the Medical and Chirurgical Society of London, by this ingenious Swede, goes largely into the subject. Blood he makes the principal object of his inquiry. The fibrin is subjected to the action of caloric by boiling in water to alcohol-to æther-to acetic acid-to weak muriatic, nitric, and sulphuric acid-and to caustic alkali. The chemical properties of the coloring matter are inquired into by a similar process; and a particular investigation is instituted for ascertaining the influence of iron for producing the color of this matter. If, as our countryman, Mr. Brande, has asserted, the coloring matter of blood is intirely independent of iron, this part of Dr. Berzelius' inquiry is extremely futile. The serum, the albumen, and the salts of the blood, become also subjects of this chemist's attention. If it is incompatible with our design to go into them with the ingenious author, it will not be unacceptable to our readers to be made acquainted with the results of Dr. Berzelius' labors on this part of his subject.

"Blood is composed of one portion, which is liquid and homogeneous, and of another which is only suspended, and spontaneously separates when at rest.

"The liquid part is a solution of much albumen and a little fibrin, both combined with soda. It also contains some other saline and animal substances, but in very small quantity.

"The portion which is suspended is the coloring matter. It differs from the albumen chiefly in its color, and its insolubility in serum. The color seems to be owing to iron, of which it contains per cent. of its weight, but which cannot be separated from it as long as it continues to be coloring matter. This separation can only be effected by combustion, or by the concentrated acids, both of which agents entirely decompose the substance with, which the metal was combined. The coloring matter cannot be artificially produced by uniting albumen with red sub-phosphate of iron. "Fibrin, albumen, and coloring matter, resemble each other so closely, that they may be considered as modifications of one and the same substance. These three substances pro, NO. 173. duce,

duce, when decomposed, but do not contain, earthy phos phates and carbonate of lime; and indeed the entire blood contains in solution no earthy phosphate, except perhaps in too small a quantity to be detected.

"The albuminous contents of the blood will unite with acids, and produce compounds, that may be termed saline; these, when neutralized, will dissolve in water, but separate on adding an excess of water. Nitric acid, digested with the albumninous contents, forms an insoluble compound, consisting of albumen in an altered state, and of the nitric and malic acids. This property of combining with acids, is retained in some instances by the albumen, after it has undergone the changes produced in the secretory organs; as, for instance, in the peculiar matter of the bile, milk, &c.

"The blood contains no gelatine."

The secreted fluids, though obscure as to their mode of formation, are highly important in their results, either as performing some office in the animal economy, or as unloading it of something that would be oppressive if retained. These secreted fluids are divided into two classes, one of which is intended for some ulterior process in the system, the other to be directly discharged from the body. It is an extremely curious fact, that the fluids of the first class are all alkalies, and those of the second all acids.

The secreted fluids noticed by Dr. Berzelius, are bile, saliva, the mucus of the mucous membrane, mucus of the trachea, mucus of the gall-bladder, mucus of the urinary passage, fluids of serous membranes, humors of the eye, fluid of perspiration, urine, and milk. Why our author has neglected to notice one of the most important of the secreted fluids, semen, cannot easily be known.

Of the peculiar biliary matter, called Pieromel by Thouard, Berzelius gives this account. It has an excessively bitter taste, followed by some sweetness; the smell is also peculiar, and the color in most animals varies from green to greenish yellow. It is soluble in water, and its solubility is not in the least promoted by the alkali of bile; since, when this is neutralized by any acid, the peculiar matter does not separate; it also dissolves in alcohol in all proportions. Like

the

the albuminous materials of the blood of which this peculiar matter is composed, it will unite with acids, producing compounds of two degrees of saturation, and hence, of solubi lity. The acetous acid, which gives soluble compounds with the albumen of the blood, does the same with the peculiar matter of the bile; and hence this matter is not precipitated on adding this acid to bile, though it falls down on the addition of sulphuric, nitric, or muriatic acids. It is this spa ringly soluble compound of biliary matter with a mineral acid which has been mistaken by many chemists for a resin ; since it possesses the external characters of a resin, melts when heated, dissolves in spirit of wine, and is again precipitated by the addition of water. The alkalies, alkaline earths, and alkaline acetates, decompose and dissolve it: the former, by depriving it of its combined acid; the latter, by furnishing it with acetous acid, which renders it soluble in water.

The peculiar matter of the bile also combines with many metallic oxides into a pulverulent mass; and the resiniform compound of this matter, and any of the mineral acids, often forms with the same oxides a substance like a plaster, resembling in this respect also the true resins.

The biliary matter may be obtained pure by mixing fresh bile with sulphuric acid diluted with three or four times its weight of water. A yellow precipitate first appears, which must be allowed to subside and be removed; then continue to add fresh acid as long as any precipitate is formed; heat the mixture gently for some hours, and afterward decant the fluid part, and thoroughly edulcorate the green resin which is left. This resin reddens bitmus, and is partially and sparingly soluble in water. It may be deprived of its acid in 'two ways: one of them is by digesting it with carbonate of barytes in water, whereby the carbonate is decomposed, and the water forms a green solution, possessing all the peculiar characters of bile: the other way is by dissolving it in alcohol, and digesting the solution, either with carbonate of potass or carbonate of lime, till it no longer reddens bitmus, and then evaporating it to dryness. Either of these methods will give pure biliary matter.

This peculiar biliary matter, when pure, resembles exactly desiccated

desiccated bile. Being soluble in alcohol it might be supposed that it would dissolve in æther, but æther only changes it to a very fetid adipocirous substance, exactly as it acts the albuminous matter of the blood. It is surprising upon that biliary matter gives no ammonia by distractive distilla tion, therefore it contains no azote; no vestige of azote in any other of the constituent parts of the bile, nor does bile contain ammonia.

1

Berzelius gives the following result of his analysis of the bile;

The researches which have been directed to animal substances by the chemists, it will readily be conceived, would not leave untouched that part of the frame which has been deemed the laboratory and store-house of intellect. The peculiar texture, appearance, and believed functions of the brain, have accordingly excited inquiries, ingenious and elaborate, which, we fear, have not yet terminated in any posi tive and indisputable conclusion. Among the various methods taken to examine the structure, and ascertain, by that means, the functions and actions of the brain and nerves, chemical analysis has been employed, with what effect future observations will determine. The abilities of M. Vauquelin in this department of science, are too well known to suffer his Analysis of the Cerebral Matter of Man and other Animals, to remain unnoticed. His predecessors, Gurman, Burrhus, Thouret, Fourcroy, &c. in the same inquiry, have not anticipated his labors. Elaborate minuteness, rigid accuracy, and an accustomed eye, combine to render this analysis important, as ascertaining the constituents of the cerebral or gan; but they do not develope its physiology.*

* This analysis of the brain, by M. Vauquelin, we think of sufficient importance to demand the insertion of the Memoir, which will be found in another part of our Journal.

The

The connection of agriculture with, and its influence on the health of man and other animals, both as it regards alterations produced by its processes on the earth's surface, and by its improvement of alimentary substances, necessarily makes it interesting to the professors of medical science; and as a branch of chemistry it approximates still more to the healing art. The deserved reputation of Sir H. Davy gives to every production of his pen great value and extensive currency and it is with peculiar satisfaction we observe his talent for investigating nature, applied to the chemistry of agriculture. In his " Elements of Agricultural Chemistry,” recently published, a very extensive experimental and scientific view is taken of this important subject. An examination of the general powers of matter upon vegetation, whether gravitation, cohesion, chemical attraction, heat, light, or electricity, is instituted; the organization of plants, the constituent parts of soils, and the nature and constitution of the atmosphere, with its influence on vegetable life, are inves

tigated with experienced acumen. An extensive experimental inquiry is made into the product and nutritive qualities of different grasses, and other plants used as the food of animals. With this cursory notice of one of the most valuable publications of the preceding six months, it does not seem to be improper to connect an elegant Essay on the Philosophy, Study, and Use, of Natural History, noticed in our preceding Number. The objects and views of this interesting little volume are most important. The study of natural history affords a sober and certain satisfaction far beyond any other human pursuit. To follow effects up to their causes, and from thence to develope other effects; to collect, arrange, and generalize individual facts, and upon them to found or explain principles, seems to be the proper employment of human intellect. "To trace," as this author happily expresses, "the footsteps of GOD, the eternal, the infinite, the omniscient, and omnipotent, throughout all Nature to be initiated in mysteries and laws which produce effects that are necessary for our welfare, or that conduce to our happiness-to seek the knowledge of His designs, and of His works, to the end that we might more

properly