BY J. M. PKTRIE. 129 



fied. Even pure atropine, when dissolved in chloroform, alcohol, 

 or water, and the solution evaporated on the water-bath, is left 

 as a syrupy residue. If these viscous semi-fluid residues be dis- 

 tilled, as described, the distillates will yield all the tests for the 

 alkaloid, and so the isolation of the "volatile, liquid alkaloids, 

 piturine and duboisine," is explained. 



The early experimenters were thrown off the track again, in 

 their attempt to solve this difficult problem, by another factor — 

 the "strong odour of tobacco." This is stated frequently in the 

 literature, and no doubt played a large part in setting the bias 

 towards nicotine. During the chemical investigation of many 

 other solanaceous plants, especially 8olandra, the Solanums, and 

 Nicotiana species, the author has noted the strong odour which 

 makes itself prominent at certain stages It is particularly 

 strong when a solution is evaporated to dryness, and when the 

 chloroform is distilled off from the last extract; and a syrupy 

 residue is left, which contains the crude alkaloids. This residue, 

 in all the cases Just mentioned, possessed this peculiar odour — 

 powerful, nauseous, and disagreeable. It somewhat resembles 

 very stale nicotine or conine, but is due to a volatile essential 

 oil which is probably present in all these plants. It was isolated 

 from the steam-distillates previously described, by acidulating 

 and shaking out with ether. When the ether was slowly re- 

 moved at air- temperature, the residue exhibited all the objec- 

 tional properties described. This residue gave no alkaloidal 

 reactions. 



It is thus shown that the statements "a volatile, liquid 

 alkaloid possessing the odour of tobacco," and "consisting of 

 atropine or hyoscyamine," are both correct, and in accordance 

 with experimental facts. 



" Duboisine." 



xviii. The chemical history of the midriatio alkaloids, which 

 have been isolated from Duboisia myoporoides, possesses peculiar 

 interest and importance. " Duboisine," the commercial crude 

 drug, is still extracted, and is found in commerce as the total 

 mixed alkaloids. In 1912, Merck's pure crystallised duboisine 



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