__ of the water, giving us therefore, * 
Scheerer on Isomorphism. 203 
First Group. 
CG Mg H- 
L Triply hydrous two-thirds carbonate 2 
~_ of magnesia, according to Fritzsche, 3267 47-23 20-10 
cordin ae 45°. 21° 
3 Magnesia alba, accontele to Klaproth, 33: 40: 27: 
a alba, according to Bucholz, a 6 6SSlCOe 
5. 5 Maly h drated, simple carbonate of , - ra 
magne according to Soubeiran, . 31:50 29-58 38-29 
6. The same a according _ , 
Berzelius 315 296 38-9 
7. The sathe compound, seedtding a: ton Se 
Bucholz, ejb 30: 30: 40° 
The relditve biiatitiot of oxygen im Gay apa tae are, 
1. 23-73 : 1828:1787 |° %. 22-90: 11°45 ; 34-60 
2. 24-72: 17-42:1867 | 6. 2290: 11°46 : 34-62 
3. 23-99 : 15'8 + 24-03 7. 2181; 11-61 ; 35-56 
4, 23:26 : 12-77: 3115 
Looking upon ‘the whole of the water contained..in these salts 
as basic, so that one atom Mg may ‘be anges 3H, oe so 
modify the ratios ef oxygen as stated ab at the oxygen of 
the magnesia becomes increased by the third: att 
1. 2373C: hess: 1 14-87)-<0fadiie 
_. B BA72 3 (1742414 18:67) =23: ; 
23:99 +: (15-48+1 24-03) = 23-49 
23:26. : (12-7711 31-16)=22'82 
: (11-45-41 34-60) =22-98 
22-90 (11: 46+1 24-623 03-00 
21-81 ; (11-6143 35-56)=23-46 
The mean of these seven OXY, ‘ratios of C : (Mg) gives us 
23°33 38. 
The quantity of oxygen in the acid is therefore precisely equal 
to that in the base, and consequently these salts, whose composi- 
tion is apparently so different, whose quahtity of —— varies 
from 47-23 to 30, and whose amount of water es between 
a ES 
wo 
rh) 
Te) 
S 
ang 
, 20-1 and 40, may be brought under the. ‘ioatanet formula 
(Mig) C, and, be feplengied a by the general title of semi-carbonate 
ydro-magnesia. erence to the causes whence it was 
ae: about that bio ¢ teh or less portion of. Mg was replaced 
a pa ae that is 3H, it is Fone of remark, that thé salt contain- 
most water was formed at a low t pos eee be be- 
in ay and 10° centigrade), whereas the salt ng the 
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eee Z 
