322 W. Gibbs and F. A. Genth 
with chlorhydric acid chlorid of Purpureocobalt is formed, 
which may be employed in preparing a fresh portion of the acid 
prismatic crystals, which, according to Prof. Dan ong to the 
trimetric system, and are hemihedral. The observed forms are 
L, t%, $4, 22, 7 (?) or in other symbols 2, oc-%, $-&, 157, £2 (?): 
8. 
PI 106°, 
I: i = 127° (126° 50’—127° 10’) 
40: 4% = 122° 497, 
13:13 = 67° 54’, 
420: ¢ == 1092771: 13271. 
£3 4a 
ear 8 represents an end view of a crystal of this salt; 12 6 
hemihedral and 73 usually so; the symbol #2 is probably cor 
though the observed angle varies much. ad 
The acid sulphate is very soluble in water, and has a distinct 
though not strongly acid taste. It reddens litmus, and expels 
carbonic acid from the carbonates. 
~ The formula of this salt is 
oie _. 5NHs.Co20s, 480:+5H0 
as the following analyses show: — 2s. 
