ON DETECTING THE PRESENCE OF WATER IN SUBSTANCES. 261 
ON A PROCESS FOR DETECTING THE PRESENCE OF WATER IN 
VARIOUS SUBSTANCES. 
By A. Gorgue. 
The presence of water in the alcohols and ethers may readily be 
detected by taking advantage of the property they possess of ren- 
dering benzine turbid when they contain water. 
The only condition requisite for ascertaining the presence of 
water in a liquid is, that it must be soluble in the benzine. The 
following is the plan of operating, for instance, with alcohol : — It 
suffices to pour one single drop into 3-4 cub. centims. of benzine. 
If the drop falls to the bottom of the tube in which the experiment 
is made without producing any turbidity, the alcohol contains 
more than a third of its weight of water. To be convinced that 
the alcohol contains too much water for any opakeness to be pro- 
duced, it suffices to add some absolute alcohol to a small quantity 
of the liquid, and to repeat the experiment. Every time that there 
is a production of turbidness, accompanied with the formation of 
little globules, we may be certain that the strength of the alcohol 
will be comprised between 65 and 93 centesimal degrees. If but 
a cloudiness be produced, the liquid contains at the most seven- 
hundreths of water. In this case the opacity may be made to dis- 
appear by the addition of some stronger alcohol. The experiment 
is made with benzine saturated with water, in little short dry tubes 
closed at one end, and of about 12 milliras. in diameter. 
When an ether is to be examined, essential oil of turpentine is 
preferable to benzine, as the turbidness produced is more persist- 
ent. It is not employed to detect the water in the alcohols, from 
its being less sensitive than benzine ; in fact, an alcohol of 98° no 
longer renders it turbid. 
By operating as I have stated, from seven- to eight-thousandths 
of water can be readily detected in an alcohol, and from three- to 
four-thousandths in an ether. 
Any substance soluble both in the liquid under examination (al- 
cohol, ether, &c.) and in the test for water (benzine, essential oil 
of turpentine, &c.) does not affect the sensitiveness of the process, 
which however is impracticable whenever one of the first liquids 
holds in solution a substance insoluble in the latter. 
