Translations and abstracts from the French. 26% 
pears to have been noticed by others. Carbonate of lime 
pact and stalactitic spar, varied in the extremes, from 2.7041 
“ 2.7234. Pure arragonite, crystallized, fibrous and fibro- 
compact, varied from 2.9467 to 2,9053; coralloid trans- 
lucid, 2.8321; opake, 2.7647. Malachite, pure, from 3.5907 
3.3496, Carbonate of lead, from 6.7293 to 6.7102. Sul- 
phate of lime, from 2.3257, in ‘small crystals, to 2.2615, nivi- 
form. Sulphate of strontian, from 3.9593 to 3.9297, Sul- 
phate of lead, from 7.7593 to 7.7398. Quartz, pure, from 
2.6541 to 2.6354. It results from the researches of M. Beu- 
dant, that small crystals always have the greatest specific 
gravity, and hence it follows that itis in small crystals we are 
to look for the greatest homogeneity, as ha has 
been long known, the greatest perfection in form. 
The lowest specific gravity is always end in the fibréus 
or epigene varieties. Hence it appears that the difference 
of specific gravity in the same substance, depends on the 
manner in which the rudimental crystals are aggregated to 
form masses more or less considerable, and M. Beudant has 
accordingly found that when reduced to powder, all the 
varieties of the same a out woe —_ _ 
ise specific gravity of the substance be seth a minera- 
ogical character, i reducing it to powder, and allowing it 
3 eee the liquid which serves as a common measure. 
When thus treated, the following is given as the specific 
gravity of the eight following substances, which is constant 
in all the gegen and which may serve to distinguish them 
when pur 
Carbonate of ligre--rhomboidel, - 2.7231 
Arragonite, i 2.9466 + 
chite - - - 3.5904 
Carbonate of lead, - i toe - 6.7290 
Sulphate of lime, dois! ti: se 
Sulphate of pores . - - 2.9592 
Sulphuret of flead, eieecd ty gee SISOS 
Quartz,  - it ey ee - 2.6540 
Idem. 
