382 
3. Preparation of the mixtures, method of observation. 
Commercial ether (Pharmacopoeia Néerlandica) was twice shaken 
with strong sulpburic acid, and dried first on sodium sulphate, then 
on sodium. It was preserved in this condition; for the preparation 
of every mixture part of this stock was distilled. As second component 
distilled water was used. For the preparation of the mixtures use 
are 
Fig. 1. 
was made of the apparatus represented in fig. 1. Each of the com- 
ponents was weighed in a small thin-walled glass bulb provided 
with a capillary stem, and put in the tubes A and B, which were 
then fused to at their tops. The Cailletet test tube of combustion 
glass HD was connected with the filling apparatus in reversed 
position by means of a rubber tube surrounded by a mercury joint. 
Near its end D the tube is widened to enlarge the volume, which 
enabled us to perform the experiments with a comparatively large 
quantity of substance. This was necessary, because exclusively concen- 
trations on the ether side were examined for this investigation; if a 
Cailletet tube of the ordinary shape had been used the quantity of 
water used would have been too small for accurate observations. 
The part of the apparatus represented in fig. 1 was connected 
by means of the glass spiral M with two tubes with cocoa-nut 
carbon, a Geissler tube, and a water-jet pump, which served to 
