Progress of Foreign Science. 399 



Nitrate of Bismuth. 



Neutral. Acidulous. 



Oxide ... 1 atom ... 1 atom 

 Acid ... 2 ... 5 



Proto-nitrate of Mercury. 



Oxide ... 1 atom ... 10 atoms 

 Acid ... 1 ... 11 



Deuto-nitrate of Mercury. 



Oxide ... 1 atom ... 4 atoms 

 Acid ... 2 ... 11 



If it be considered, moreover, that water alone, in saturating 

 the nitric acid, can decompose the sub-deutonitrate of mer- 

 cury, it will appear evident that it is not acidulous nitrates 

 which are here formed, but a combination of neutral nitrate, 

 water and acid ; where the acid acting at once both on the wa- 

 ter and on the neutral nitrate, prevents this from being subse- 

 quently decomposed by a new quantity of water. 



On the above statements of M. Grouveile, we have only to re- 

 mark, that the formation of his salts, does not seem sufficiently 

 determinate to warrant all his atomical inferences. We do not 

 believe, for example, in the existence of a compound of ten 

 atoms of oxide of mercury, and eleven atoms of nitric acid. — 

 Annales de Ck. et de Phys. xix. 1 37 . 



Analysis of a Salivary Calculus of a Horse, and of the Saliva 

 of the same Animal, by M. J. L. Lassaigne. — This concretion 

 had a cylindrical form, resembling that of an elongated ellipsoid. 

 Its length was forty-seven millimetres, and its diameter eighteen. 

 It was as hard as marble. It consisted of concentric coats, 

 without any central nucleus of foreign matter. Its constituents 

 were 



Carbonate of lime 84 



Phosphate of lime 3 



-\nimal matter 9 



Water 3 



Loss 1 



Too" 



This result, along with the others already known, demon- 

 strate that the salivary calculi found in herbivorous animals, are 

 generally different from those which occur in man, which con- 

 sist of phosphate of lime, with a little animal matter. 



The saliva of the horse, when evaporated at a moderate heat, 

 leaves 3| parts in the hundred of fixed principles, which ar« 

 composed of the following ingredients; 

 2 E 2 



