The author commences by laying down the principles on which he supposes the action of poisons may be explained :—1. Poisons are unassimilable substances. 2. They pass into the organism by absorption. 3. Their action is that of presence. If these principles be correct, it follows that all poisonous substances, whatever they may be, must be found in the organs with which they ha ve been brought into contact, or to which they have been transported by absorption. In the case f the inorganic poisons, experience has shown * there is no exception to the rule. It still ic aim to be shown that the same rule applies to the organic poisons, i Christison states, with regard to opium, that as a general rule the medical jurists can scarcely obtain satisfactory proof of the existence of this substance by the best methods of analysis at present known. Now the best methods of analysis known at present for ascertaining the presence of opium, and of the organic proximate principles in general, consist in treating the suspected substances cither with acetic acid or alcohol, filtering the liquid, and evaporating it to the consistence of an ex-trac'a. This extract is then re-dissolved in I water, either pure or acidified, and decolor- j ized by animal charcoa1, m j' mm It""" ters are precipitated a f ? i o I Vy tious reagents (such a UJ u tM lead, " I phuretted hydrogen, nitrate i hei a. Lastly, the extractive matter i obt in i I tested by different re agents, such H * it ' acid and perchloride o( iron, wilt I i i J red to ascertain the iic e u ot p rpK it, I t , active principle of opiu n In i JP hv ever, no satisfactory ie ul u be u' The poison is not isolated , it ot C'I ' acted upon by the re-agents; its characteristic properties consequently cannot be ascertained. The author considers that animal substances may be divided as /allows, — -i. .Fi-uieine or albuminous substances. 2. Coloring matter. 3. Fatty substances. The proteine substances are readily coagu-lable, and in this state they become insoluble in water, alcohol, acids, &c. The colored or coloring matters are easily changed by various acids and alkaline agents, anhydrous lime and baryta for instance, without mentioning heat. The fatty substances are separated with ease from all the other matters by alcohol asd ether. Now, if an inorganic substance be mixed with organic substances, there is nothing more easy than, to discover it. The organic substance is burnt, the inorganic principle is brought to the state of a soluble compound within the cinder, and then extracted with water. The process of carbonization or inci-deration by means of sulphuric acid for the discovery of the mineral poisons is founded on these very simple data. But if the substance which it is necessary to separate from animal matters be combustible, or capable of essential modification by heat, the course is not so clear. The following is the process proposed :— To 100 parts of the substance to be examined, 12 parts of anhydrous lime or baryta are to be added, and the whole pounded to-getnor in a mortar. The mixture is then to be heated to 212 Fah., then pulverized, either with a pestle, or with a special apparatus appropriated to this operation, which is very essential; the powder is to be treated with boiling anhydrous alcohol three times, filtering the liquid after cooling. This liquid as it leaves the filter is scarcely colored ; it only contains the proximate principle or principles sought for with the fatty or resinous matters. The alcohol is now slowly evaporated, and the dry residue treated with ether to remove the fatty matters. It the principle be insoluble in ether (morphine, strychnine, brucine,) it will be separated in the fluid, and may be obtained by filteration or simple decantation. . If it be soluble in ether, the alcoholic residue or the etherial fluid must be treated with a special solvent of the organic bases, such as the acetic acid, precipitating the base afterwards by ammonia. To 100 grms. of animal matter the author added a single grain or 0'05 grm. of morphine, strychnine, and brucine ; and by operating in the manner just described, succeeded in obtaining, in a state of absolute purity, a ponderable quantity of each of those principles.— Instead of strychnine, morphine, and brucine, the author applied crude opium, laudanum, decoction of nux vomica, and of false angostura bark ; and in these cases also he was able to isolate the poisonous principles. He also, in order to assure himself that his process was applicable to medico-legal purposes, poisoned animals with the smallest effective doses of the above-mentioned substances, when he was able to detect the poisons in the matters contained in the stomach and intestines, and sometimes even in organs to which they had bail! carried by absorption. ID oee , xneriment, he mixed 2 grs. (or 10 centigrms.) "i morphine with 100 grms. ot flesh, leaving the substances to undergo putrefaction for two months. At the end of this period he discoveiwl several centigrammes of morphine in the mass.— [Comptes fiendus. [The above is very important information. A few weeks ago a young man named Hen-diickson was Jound guilty of murder at Albany, N. V., for poisoning his wife by aconitic add, principally upon the testimony of Dr. Sail Ira y, o Albany, who analyzed the sto-IT a d Di Swinburne, who made the rortsrr Mjaination—both young physi- i V b i' ting testimony by Dr. L. Reid, i nin d "nemist of New York City,: 1) mon ,ot Albany, an experienced che- and Dr. B, P. Siaats, of Albany, an ex- enced ph) "Sit an. These testified that -o iiance could be placed In the experiments f Dr. Salisbury, to prove that aconitine was administered, yet, the jury found the man guilty. All the information that can be gathered on the means of detecting organic poisons, is of great importance, as it has been held t;"!"-t.i oliryw* imp"HW. fn A* *n !r,j the majority of cases.