276 CONSIDERATION OF CARBON COMPOUNDS. 



58 and boils at 95, and also volatilizes slowly at ordinary 

 temperature. 



Chloral, and its hydrate, are decomposed by weak alkalies into 

 chloroform and a formate of the alkali- metal : 



C 2 HC1 3 + KHO KCH0 2 -f CHCI 3 . 



Chloral. Potassium Potassium Chloroform, 



hydrate. formate. 



This decomposition was believed to take place in the animal 

 body, and especially in the blood, whenever chloral was given 

 internally, but recent investigations seem to contradict this 

 assumption. There is no chemical antidote which may be used 

 in cases of poisoning by chloral, and the treatment is, therefore, 

 confined to the use of the stomach-pump and to the maintenance 

 of respiration. 



Chloroform, Chloroformum, CHC1 3 = 119.2 ( TricMormethane, D<- 

 chlormethyl chloride). When chlorine, bromine, or iodine is 

 allowed to act upon methane, CH 4 , a number of substitution 

 products are formed. Thus, if methane is considered as methyl 

 hydride, CH 3 H, the first product of substitution is methyl chlo- 

 ride, CH 3 C1 ; the second is monochlormethyl chloride, CH 2 C1C1 ; 

 the third is dichlormethyl chloride or chloroform, CHC1 2 01 ; and 

 the fourth is carbon tetrachloride, CC1 4 . Similar products are 

 formed by the action of iodine or bromine upon methane, or, 

 in fact, upon any of the paraffines. 



Chloroform is, however, not obtained for practical purposes 

 by the above process, but by the action of bleaching-powder 

 and calcium hydrate on alcohol. The three last-named sub- 

 stances, after being mixed with a considerable quantity of 

 water, are heated in a retort until distillation commences ; the 

 crude product of distillation is an impure chloroform, which is 

 purified by mixing it with sulphuric acid and allowing the mix- 

 ture to stand; the upper layer of chloroform is removed and 

 treated with sodium carbonate (to remove any acids) and dis- 

 tilled over calcium oxide (to remove water). 



The explanation of the formation of chloroform by the above 

 process has indirectly been given in connection with the con- 

 sideration of chloral, where it. has been shown that alcohol is 

 converted by the action of chlorine first into aldehyde and sub- 



