1869.] Chemistrij. 531 



turns green, probably from oxidation, as the change of colour is 

 accompanied by an increase of weight. The base itself, newly pre- 

 cipitated, is white, but it speedily turns green on exposure to air. 

 The green mass is partly soluble in water, communicating to it a 

 fine emerald colom' ; it dissolves in alcohol, yielding also a green 

 tint, in ether giving a magnificent rose-purple, and in chloroform 

 giving a fine violet tint. 



The physiological effects of apomorphia are very different from 

 those of morphia : a very small dose produces speedy vomiting and 

 considerable depression, but this soon passes off, leaving no after-ill 

 effects. Dr. Gee is now studying these effects, and has found that 

 y^th of a grain of the hydrochlorate subcutaneously injected, or 

 ^ grain taken by the mouth, produces vomiting in from four to ten 

 minutes. Mr. Prus allowed himself to be injected with -r„th grain, 

 which produced vomiting in less than ten minutes. From Dr. Gree's 

 experiments on himself and others, he concludes that the hydi'o- 

 chlorate is a non-irritant emetic and powerful anti-stimulant. From 

 these properties it appears probable that it may come into use in 

 medicine. 



M. Hager observes that, although elementary chemical analysis 

 of caffeine and theine yields results which would conclusively prove 

 the identity of these two substances, yet the author found that the 

 physiological effect, after partaking of a dose of '25 grm. of both 

 substances chemically pure, is by no means the same. The human 

 organism is imbued with testing powers, compared with which 

 chemical reagents are of httle dehcacy. 



Dr. Hofmann has described a convenient method for the forma- 

 tion of ferric acid. An intimate mixture is made of one part of 

 ferrum limatum, and two parts of nitrate of potassa ; these are 

 heated in a small glass flask over a strong gas flame ; the mixture 

 soon becomes quite incandescent, emits out of the mouth of the 

 flask a firework of sparks, and leaves at last a mass partly fused 

 into the glass of the flask, consisting of ferrate of potassium. 

 After cooling, this mass is reduced to powder, and being exhausted 

 with water, yields a deep-reddish violet-coloured nearly transparent 

 solution. 



Commercial chloroform is frequently adulterated with alcohol 

 and ether, and it is sometimes of importance to ascertain whether 

 these impurities are present in any given sample. In order to 

 discover this, the chloroform should be first treated with fused 

 chloride of calcium to eliminate any water; next some "iodine must 

 be added. If the chloroform is free from either alcohol or ether, 

 the colour produced by the solution of the iodine is bright red ; 

 but when either alcohol or ether is present, the colour of the solution 

 is brown. In order to distinguish between alcohol and ether, a 



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