retains water. When we further bear in mind that the hydrate is 
only constant below 0.35° under atmospheric pressure, and that, 
accordingly, formation of the hydrate at atmospheric pressure without 
formation of ice will only be possible between O° and 0.85°, it will 
be clear that we must here have recourse to special methods of 
analysis. IT shall have to postpone a description of a method suitable 
for this purpose to a following communication; it may only be 
mentioned here that even the formula H,5.6H,O derived later by 
DE ForcrAND on theoretical grounds probably still contains too great 
a quantity of water. 
(February 23, 1911). 
