SALIVARY CONCRETIONS. 573 



ed of concentric layers, very distinct, but having the same co- 

 lour. It had a nucleus, in the centre of which was a small piece 

 of dog-grass, round which, in all probability, the concretion had 

 formed. It had no taste, but a disagreeable foetid smell. Its 

 specific gravity was 2-209. Its constituents, according to the 

 analysis of M. Henry, were, 



Carbonate of lime, . 85*52 



Carbonate of magnesia, . 7 '5 6 



Phosphate of lime, . . 4*40 



Phosphate of magnesia, trace. 

 Common salt, . . 0*04 



Organic matter and loss, . 2 '48 



100-00 



3. In 1825, M. Lassaigne analyzed a salivary concretion tak- 

 en from the duct of the parotid gland of an ass, and remarkable 

 for its large size.* It was as big as the fist, its shape was ovoid, 

 its surface smooth and white. Its hardness was about the same 

 as that of marble, and its weight 620 grammes, or very nearly 

 I Ib. 6 oz. avoirdupois. Its specific gravity was 2*302. 



Its constituents, as determined by the analysis of Lassaigne, 

 were, 



Water, . . . 3-6 



Soluble principles of saliva ; soda, animal matter, soluble \ i .Q 



in alcohol, chloride of calcium, sulphate of lime, &c. / 

 Mucus, . . . .6*4 



Phosphate of lime with trace of iron, . 3*0 



Carbonate of lime, . . . .85*1 



99*1 



From this analysis it appears that the salivary concretion of 

 the ass agrees very nearly with that from the horse, previously 

 examined by M. Lassaigne, and stated above. 



4. 'To M. Lassaigne, also, we are indebted for the chemical 

 analysis of a salivary concretion from a cow. It was white, hard, 

 capable of being polished, about the size of a pigeon's egg, and 

 its nucleus was an oat seed. It consisted of carbonate of lime 

 mixed with a little phosphate of lime and some animal matter, f 



5. M. Vauquelin, in 1817, analyzed a concretion found in the 



* Ann. de Chim. et de Phys. xxx. p. 332, f Ibid. ix. p. 326. 



