1886.1 NEW YORK ACADEMY OF SCIENCES. 197 



These are substances of little stability, as indeed might be 

 expected. 



Professional clieniists also acknowledge the marvellous success 

 in unravelling the complications of isomerism, and the important 

 aid afforded the study of isomeric bodies of the aromatic group 

 by the doctrine of orientation. These rather technical details 

 can receive, however, but brief mention, though a whole series 

 of lectures could be devoted to the fascinating topic. Leopold 

 Gmelin, when writing his "Handbook of Chemistry," in 1827, 

 requested organic chemists to stop making discoveries, or else 

 he could never finish ! And during the sixty years wiiich have 

 elapsed, the activity in organic cliemistry has been unceasing; 

 yet the extraordinary number of facts now known is not so great 

 as those which the prophetic eye sees disclosed by these recently 

 revealed lines of investigation. 



(20.) The crowning glory of chemistry is the power of produc- 

 ing, in the laboratory, from inorganic matter, substances identi- 

 cal with those existing in the vegetable and animal kingdoms. 

 Belief in the mysterious vital force operating in living beings re- 

 ceived a rude shock at tiie hands of Wohler, sixty years ago, and 

 successive triumphs in synthesis have dispelled it entirely, so far 

 as non-organized bodies are concerned: ''to-day we know that 

 the same chemical laws rule animate and inanimate nature, and 

 that any definite compound produced in the former can be pre- 

 pared by synthesis as soon as its chemical constitution has been 

 made out.'' Within a few years chemists have announced the 

 synthesis of many acids, essential oils, alkaloids, glucosides, 

 dye-stuffs, and other bodies naturally occurring in the organic 

 world, and so rapidly do these announcements succeed one 

 another that expectation has displaced surprise. Noteworthy are 

 the following : alizarine, the valuable coloring matter of mad- 

 der ;°* vanilline, the aromatic principle of the vanilla bean;" 

 cumarine, the aromatic principle of the tonka bean;'" indigo, 

 the well-known dye-stuff" ;" uric acid, an animal product ;" tyro- 

 sin, likewise a product of the animal organism ;''^ salicine,'^ daph- 

 netine and nmbelliferone," natural glucosides and related 

 bodies; piperidine,'" a constituent of pepper; and cocaine, the 

 new anesthetic." Besides these, many s^^ntheses have been 

 accomplished of bodies isomeric and not identical with the 

 natural products. 



