“ a " re Sd 
The 4 aq. are driven off at 262°-4F. The gene sul 
Pigg shee 
& Researches on Salts. 341 P 
I have since obtained the subnitrate of zine in the form “4 
ismatic needles, containing, as in th ceding exam 
{N: 205, 4Zn? O, “SH? Q]. The formul ’ Schindler and of 
Grouvelle are not e exact. These chemists analyzed mixtures ; 
and consequently failed to notice that the precipitate produced 
by aoe in nitrate of zine contains ammonia in combination 
[N? O°, 4Zn? O, H? O,N? H®*], which is not the case in nitrate 
of copper. - There are then three subnitrates, having a precisely 
similar composition, and the same water of constitu 
Subnitrate of iets Pb: NO*(Pb* H*)=N? O*; 4Pb? 0,3H? 0 
of Cu: NOs (Cut BBN? 0+; ACu? O, 3H* Oxgr 
& “ of Zn: NO*(Zn* H*)=N? Os, AZn? 0, 3H*OF 3 
I think I can safely affirm that the subnitrates of cobalt and of 
nickel present a similar composition ; however, as I have not op- 
erated upon salts of nickel entirely free from cobalt, and vice + 
versa, I do not advance this opinion unreservedly. a 
Lest the analogy I have pointed out between the water of « ; 
aunt of acid salts and that of basic salts, should still seem 
ubtful, I will add another proof. When acid salts co 
cane of water (water of crystallization) greater thé 
which corresponds with the composition previously in 
know they are deprived of this excess by desiccation at a ten 
ature lower than that at which the water of constitution is. 
off. fhe Se for a the cry tle ate of pi 
c 
C:0!,K?0 
H? 0 ie 
C:03,H?0 + 4aq. - 
phate of copper contains at 212° F. 
SO*,Cu?0 
H? O, Cu? O 
The 2 aq. are also driven off between 248° F’. and 266° F.., 1 
the 3H? O resist a temperature of 392° F. The quadribasic. 
chromate of copper hi poeeey the gom position of this subsulp 
I could cite still 1 - ther subsalts, ey 
ses of which confirm : 
Their ae i 
mmoniacal ohio of zinc, 1 my- 
r I had constantly found in the two 
” (67 1 per cent.). They do contain in 
33 
