Lithiasis. 4li 



tion of bone, from the fact, that these concretionary formations 

 have not yet been distinguished from their opposites, in which 

 the formation of lime appears as a supplement of defective for- 

 mation of bone. Instances of this are in man, — tartar on the 

 teeth, salivary calculi, gall-stones, ossification of the ovaries, 

 &c, which appear in the most different individuals, and under 

 the most opposite constitutional and geographical relations. 

 We find many analogies in the lower animals, in the forma- 

 tion of concretions and of pearls by mollusca, of the stones in 

 the intestines of the crab, of the salivary concretions of the 

 cetacea, &c. That they must be regarded as supplements to 

 defective formation of bone, is plain from the following facts : 

 1. Their occurring most frequently under those circumstances, 

 and among those classes of animals and individuals, in which 

 this deficiency is most obvious. 2. Their periodical appear- 

 ance and disappearance in accordance with the changes in 

 the osseous system, for instance the stone in the crab, with 

 the changing of its shell. 3. The entirely different chemical 

 constitution of the supplementary from the complementary 

 concretions. The connecting organic matter is also of much 

 less importance and in less quantity, and bears a small per- 

 centage to the whole mass. 



The foregoing observations are compiled from papers by 

 Drs. Heusinger and Escherich. The interesting, but rather 

 vague views thrown out by them, are intended merely as pos- 

 sible hints towards a rational pathology of calculous diseases. 

 A careful enquiry into the diffusion of lithiasis in India, (like 

 that of Mr. McClelland, into the diffusion of goitre in Ku- 

 maon) would be valuable, as at present we possess no accurate 

 information on the subject. 



In 1831, Mr. Burnard wrote an interesting paper, contro- 

 verting the received opinion in Europe, that Calculus was 

 rare in India, as in all tropical countries. About that time it 

 had been suggested, that the frequency of stone in Norfolk 



