ON THE STRUCTURE OF CALCULI. 39 



N 



are farther characterised by their solubility in dilute muri- 

 atic acid. 



3. Calculi containing oxalate of lime ; commonly called W" 1 ,? 1 oxala t« 

 ., . .. D f of hme, or 



mulberry calculi. mulberry eai- 



- These are distinguished by the difficulty with which they culi - 



dissolve in dilute acids, by their hardness, and by leaving 



pure lime, when exposed to the action of the blowpipe. 



In the examination of these calculi, I was struck with the 

 small number of those strictly belonging to the first divi- 

 sion, having been led, from the account of Fourcroy and 

 Vauquelin*, and the experiments of Dr. Pearsonf, to be- 

 lieve that calculi, composed of pure uric acid, were by no 

 means unfrequent. 



The greater number of the calculi examined by the for- 

 mer chemists are stated to be completely soluble in the 

 fixed alkaline lies; and of three hundred examined by Dr. 

 Pearson, a large proportion is said to consist of uric acid. 



The following is a statement of the composition of the Composition 



different calculi found in the bladder which I have exa- of different 



. calculi. 



mined. 



16 were composed of uric acid. 



45 , uric acid with a small relative pro- 



portion of the phosphates. 



66 i . i the phosphates, with a relatively 



small proportion of uric acid. 



J 2 1 . ■ of the phosphates entirely. 



5 ■ . — • of uric acid, with the phosphates 



and nuclei of oxalate of lime. 



6 ■ chiefly of oxalate of lime. 



150 



- 



To injure these calculi as little as possible, they were Sawn in two 

 carefully cut through with a fine saw, and a portion of the an< * a portion 

 whole cut surface removed by a file ; in this way all the dif- ° ' 

 ferent ingredients of the calculi were obtained. 



In the experiments upon uric calculi from the bladder, I More loss from 

 found, in most instances, a far more considerable loss in at- tllose ©f toe 



* Annales de Chimie, xxxii, ai8. 

 •fr Philos. Trans. 1798. p. 37. 



tempting 



