(SAE) 
if one tries to liberate hydrazine from the aqueous solutions of its 
salts by bases, it is always combined with water and yields on 
distillation a hydrate of the composition: N,H,-H,O which boils at 
119° and in which the water is very firmly united with the hydrazine. 
Since free hydrazine (b.p. 113°.5) had become accessible it was 
possible to investigate the whole system hydrazine + water and to 
see whether the existence of Currius’s constant-boiling hydrate 
would show itself in the curve of the specific gravities of the 
mixtures. It was a priori not improbable that this should be the 
case and experiment has confirmed this idea. 
From the subjoined table in which each figure is the result of 
two or more concordant determinations and from the curve constructed 
with the aid of these figures, it appears that on mixing hydrazine 
with water a contraction takes place. It will be noticed that the 
maximum density corresponds with the formula NH,.H.0O. 
0/NoH, mol. NH, spec. weight 
on 100 a 
100.0 100 1.0114 
90.8 84.1 1.0300 
84.0 fat: 1.0358 
80.0 69.25 1.0379 
78.5 67.25 1.0400 
74.9 62.65 1.0421 
72.0 59.15 1.0440 
67.4 53.75 1.0464 
64.1) 5015 1.0470 
59.9 45.7 1.0464 
55.3 41.0 1.0461 
46.4 32.75 1.0425 
40.85 28.0 1.0389 
34.25 22.65 1.0340 
26.45 16.85 1.0272 
14.0 BA 10149 
1) Nearly NgH,4-H,0. 
