Pln/siral a)id Cliemical Papcr^^. 101 



of the chloroplatinate, from the amount of metallic platinum, 

 or directly by the decomposition of the chloroplatinate. 



By this method it has been found possible to determine the 

 strychnine in a mixture of .060 of quinine and .002 of strych- 

 nine. beiuK about the proportions found in such preparations 

 as elixir of iron, quinine and strychnine. 



In determininji- the strychnine in the elixir of iron, quinine 

 and strychnine, it would be necessary to liberate the total al- 

 kaloids and proceed with the mixed alkaloids as directed. The 

 quinine can be determined by difference or from the filtrate 

 by making alkaline, shaking- out with ether or chloroform, and 

 weighing the dried residue. 



The only interfering- alkaloid in this separation is brucine, 

 Brucine, if present, would behave similarly to strychnine. 

 Dionin, morphine, narcotine, codeine, heroin, atropine, col- 

 chicine, hydrastinine, narceine, coniine, cocaine, aconitine, 

 scopolamine, physostigmine, pilocarpine, theobromine, cin- 

 chonine, antipyrine and caffeine are not precipitated from their 

 acid alcoholic solutions. It is the rule, however, that most al- 

 kaloids are precipitated from their alcoholic solutions. The 

 exceptions are dionin, atropine, colchicine, narceine, coniine, 

 aconitine, theobromine, antipyrine, and caffeine. Dionin, col- 

 chicine, coniine, theobromine and caffeine are not precipitated 

 from any of their solutions by the platinic chloride reagent. 



