Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/544

 that the medical inspector know the real extent of his resources; and it has appeared to me that, greatly as the hand of the chemist has been strengthened by late discoveries in vegetable analysis, his power has been overrated both by his scientific brethren, and by the medical profession generally. I am happy to find, since the first publication of these remarks, that they coincide with the experience and opinion of so eminent an authority as Professor Buchner; who has observed that a chemical analysis must often fail to detect opium where there could be no doubt of its having been administered in large quantity.

It is of moment to add, that in two of the instances mentioned above the odour of laudanum was perceived in the subject of analysis,—faintly, however, and only for a few hours after it was removed from the stomach. Although the peculiar odour of opium is a delicate criterion of its presence, it does not follow that it should be preferred to an elaborate chemical analysis. For it is a test of extreme uncertainty. There is in the contents of the stomach such a complication of odours, that with a rather delicate sense of smell, I have sometimes been unable to satisfy myself of the presence of the opiate odour where others were sure it existed. At the same time the medical jurist should not neglect it as a subsidiary test. It is always strongest and most characteristic, first, when the stomach is just opened, or the contents just withdrawn, and again, when the fluid, in the course of preparation, as directed in paragraph 1 (p. 535), is just reaching the point of ebullition. The latter odour is somewhat different from the former, yet quite peculiar, and such as every chemist must have remarked on boiling an infusion of opium. It is further to be observed, that although the odour of opium is a very delicate test of its presence even in complex organic mixtures, chemical analysis may be successful, where this character fails. Dr. Morehead of the Bombay service, in applying my process to the fluid withdrawn by the stomach-pump, detected morphia both by nitric acid and perchloride of iron, although he could not detect any odour of opium in the fluid.

So much for the delicacy of the process. As to its precision,—from what I have myself witnessed, as well as from the experience of Dr. Ure, it will often happen in actual practice, that the only indication of opium to be procured by the process consists in the deep, has attacked in no very measured terms this opinion of Professor Buchner and myself. But, although he professes to give a literal translation of the passage above, he has translated it so incorrectly as wholly to misrepresent our opinion. The close of the paragraph, "chemical analysis must often fail to detect opium where there could be no doubt of its having been administered in large quantity," is rendered into French by the Parisian Professor in these words,—"l'analyse chimique, propre à constater l'existence de l'opium, est souvent inutile, même dans le cas ou il existe une grande quantité de cette substance,"—which is a very different proposition. Orfila clearly overrates the utility of the process for detecting opium, both in this criticism and in his whole observations on the subject, by losing sight of the tendency of absorption to remove the poison beyond reach.]