§§ 197) I 9^-l CHLORAL. 165 
Trichlor-acetic acid is decomposed in a similar manner. 
Statistics. —Chloral caused, during the five years ending 1916, in 
England and Wales, 17 deaths—viz. 16 (12 males, 4 females) accident¬ 
ally, and 1 female from suicide. 
Chloralose is obtained by heating anhydrous chloral with glucose. 
Chloralamid, CCl 3 CH(OH)NIE, has the toxic properties of chloral. 
Dormiol is dimethylethylcarbinol chloral, a colourless liquid compound 
of chloral hydrate and amylene hydrate. 
§ 197. Detection. —It is, of course, obvious that after splitting up 
chloral into chloroform, the latter can be detected by distillation and 
applying the tests given at p. 162 et seq. Chloral hydrate is soluble 
in one and a half times its weight of water ; the solution should be 
perfectly neutral to litmus. It is also soluble in ether, in alcohol, and 
in carbon disulphide. It may be extracted from its solution by shaking 
out with ether. There should be no cloudiness when a solution is tested 
with silver nitrate in the cold ; if, however, to a boiling solution nitrate 
of silver and a little ammonia are added, there is a mirror of reduced 
silver. 
§ 198. The assay of chloral hydrate in solutions is best effected by 
distilling the solution with slaked lime ; the distillate is received in 
water contained in a graduated tube kept at a low temperature. The 
chloroform sinks to the bottom, and is directly read off ; the number 
of c.c. multiplied by 2-064 equals the weight of the chloral hydrate 
present. 
Another method, accurate but only applicable to the fairly pure sub¬ 
stance, is to dissolve 1 to 2 grms. in water, remove any free acid by 
baric carbonate, and then treat the liquid thus purified by a known 
volume of standard soda. The soda is now titrated back, using litmus 
as an indicator ; each c.c. of normal alkali neutralised by the sample 
corresponds to 0-1655 grm. of chloral hydrate. Small quantities of 
chloral hydrate may be conveniently recovered from complex liquids 
by shaking them up with ether, and removing the ethereal layer. A con¬ 
venient tube for this purpose, suitable for either liquids which like ether 
float to the top, or like chloroform sink to the bottom, is represented in 
the accompanying illustration. A is a mercury reservoir connected with 
a graduated tube T ; a two-way stopcock S permits liquids to be drawn 
in through the thistle-head funnel or expelled by the side tube ; when 
chloroform is used it can be removed through a lower two-way stopcock 
g, by the tube cl. The ether may be allowed to evaporate spontaneously ; 
but there is in this way much loss of chloral. The best method of 
estimating minute quantities is to alkalise the liquid, and slowly distil 
the vapour through a red-hot combustion tube charged with pure lime, 
as in the process described at p. 163. A dilute solution of chloral may 
also be treated with a zinc-copper couple ; the nascent hydrogen breaks 
