_The Extract of Meat_.--Baron Liebig, who has favored us with some admirable samples of this excellent preparation, has also forwarded to us a letter in which he very clearly explains what is the exact nutritive value of the _extractum carnis_: "The meat," says the baron, "as it comes from the butcher, contains two different series of compounds. The first consists of the so-called albuminous principles (albumen, fibrin) and of glue-forming membrane. Of these, fibrin and albumen have a high nutritive power, although not if taken by themselves. The second series consists of crystallizable substances, viz., creatin, creatinin, sarcin, which are exclusively to be found in meat; further, of non-crystallizable organic principles and salts (phosphate and chloride of potassium), which are not to be found elsewhere. All of these together are called the extractives of meat. To the second series of substances beef-tea owes its flavor and efficacy, the same being the case with the _extractum carnis_, which is, in fact, nothing but solid beef-tea--that is, beef-tea from which the water has been evaporated. Beside the substances already mentioned, meat contains, as a non-essential constituent, a varying amount of fat. Now neither fibrin nor albumen is to be found in the _extractum carnis_ which bears my name, and gelatine (glue) and fat are purposely excluded from it. In the preparation of the extract the albuminous principles are left in the residue. This residue, by the separation of all soluble principles, which are taken up in the extract, loses its nutritive power, and cannot be made _an article of trade_ in any palatable form. Were it possible to furnish the market at a reasonable price with a preparation of meat containing both the albuminous and extractive principles, such a preparation would have to be preferred to the _extractum carnis_, for it would contain all the nutritive constituents of the meat. But there is, I think, no prospect of this being realized." These remarks show very clearly the actual value of the extract. It is, in fact, concentrated beef-tea; but it is neither the equivalent of flesh on the one hand, nor an imperfectly nutritive substance on the other. It is, nevertheless, a most valuable preparation, and now commands an extensive sale in these countries and abroad; and it is, furthermore, the only valuable form in which the carcases of South American cattle (heretofore thrown away as valueless) can be utilized.--_Popular Science Review_. ------ {140} NEW PUBLICATIONS. LIFE OF THE MOST REVEREND JOHN HUGHES, D.D., First Archbishop of New York. With Extracts from his Private Correspondence. By John R. G. Hassard. Pp. 519. New York: D. Appleton & Co. 1866.