438 Dr.Prouth Description of an Urinary Calculus. [June, 



The boy from whom this calculus was taken suffered extreme 

 irritation, and his general heath was much deranged. Two or 

 three weeks before it was extracted, I had an opportunity of 

 examining his urine ; it was pale-coloured, and exhibited the 

 appearance it usually assumes when a calculus is present in the 

 bladder, or when the functions of the inner coat of that viscus 

 are otherwise derangexl. Its specific gravity was 1023'8, audit 

 abounded in urea and the triple phosphate of magnesia and 

 ammonia. It reddened turmeric paper, but as it had been kept 

 for some days before I had an o))portunity of examining it, this 

 property might have been acquired after it was voided from the 

 bladder. 



I possess a fragment of another small calculus, having precisely 

 the same colour and properties as that above described. It was 

 likewise taken from a boy under the age of puberty, and was 

 accompanied by great irritation. This fiagment, which is about 

 one-tenth of an inch in thickness, appears to have constituted a 

 part of the outer crust. Its external surface is rough, and covered 

 with mamillary protuberances. To a part of its internal surface 

 there is adhering a portion of a common lithic acid calculus ; 

 probably, therefore, the whole of its centre was composed of that 

 substance. This boy, as well as the former, recovered from the 

 operation, and I believe neither has ever had any return of the 

 complaint. 



The characteristic properties of this species of calculus appear 

 then to be the following : I, their colour and general appearance^ 

 which are peculiar ; 2, their solubihty in water; 3, their yielding- 

 ammonia when treated with the fixed caustic alkalies. To 

 which, perhaps, maybe added, 4, their property of decrepitating- 

 before the blow-pipe.* 



There are also strong reasons for concluding, from the small- 

 ness of their size, and other circumstances, that this species of 

 calculus, in its pure state, is peculiar to children under puberty,-|- 

 and that it is accompanied by great derangement of the general 

 health, and the most distressing irritation. 



With respect to the medical treatment of this variety of calcu- 

 lus, it ought probably to differ in no respect from that adopted in 

 •ordinary cases of the lithic acid calculus ; certainly not at least 

 in a chemical point of view. 



51s se (roiivpnf qiiclquefois reroiiverls d'nclde nriqiie piir : la cniiclie extcricurc de 

 <:clui-ci est oidiiiairt'inent pen epiiisse, ci l;i plus graiule qURntilt: dc calcul est de 

 riiiale (raiTunoniaqtie. Siir les COO c.ilcnUexaniineii la proportion du nunibred'in- 

 tlividiis lie cclle cspecc a ele une des plus foihlos." 0|). oil. p. S37. 



• I am aware that decrepiialing calcnli are usually said In rontain a liltleoxa- 

 Jate of lime, and this was perhaps the case in both the above instances. In thesa 

 instances, however, the decrepitation appeared to mc rather to depend on the 

 «sc ipe ofainmonia. 



+ 'I'lie morbid nrine of children generally contains an excess of the ])hospha(es, 

 fciit in some rare instances a peculiar clay-colo>ired deposition lakes place after the 

 tirine has cooled, w hich, if I am not niislaken, consists partly of lilhateof aminocia. 



