328 Calculi found iti the Urinary Bladder of an Ox. 



He informed me, that he had procured them from a butcher, by 

 whom they had been found in the urinary bladder of a healthy 

 ox, killed for the market at Portsmouth. 



They were about fifty in number. The largest was little 

 larger than a grape seed ; it weighed /^ths of a grain ; — the 

 smallest were exceedingly minute, less in size than the finest 

 mustard seed, and weighed less than xoo^^ ^^ ^ grain. They 

 were all of a pearly lustre ; externally of a yellowish-brown hue ; 

 internally of a silvery white. The smallest were spherical ; the 

 forms of the larger were less regular, they were imperfect 

 spheres. Their structure was concentric lamellar. 



Before the blowpipe, they decrepitated with explosive violence. 

 When heated, confined between folds of platina-foil, so that their 

 minute fragments could be collected, they (the fragments) were 

 found to be portions of very fine laminae, which blackened when 

 farther heated, and ultimately became perfectly white. When 

 heated in a glass tube, water was collected ; to the rapid conver- 

 sion of which into steam probably the violent decrepitation was 

 owing, at least in part. I say in part, because on one occasion 

 two or three of their calculi decrepitated, at a comparatively 

 low temperature, when placed before a fire in a small glass jar, 

 covered with tin-foil and varnished, (for the purpose of rapidly 

 drying the varnish, preparatory to placing it on the shelf in the 

 Museum), — giving the idea, that electricity might be concern- 

 ed in the phenomenon. 



The ash obtained from them, after the action of the blow- 

 pipe, was bulky ; it effervesced powerfully in dilute muriatic acid, 

 and was entirely dissolved. The solution was not distinctly ren- 

 dered turbid by aqua ammonite; it was copiously precipitated 

 by the sesquicarbonate of ammonia. 



The calculi, before incineration, effervesced more slowly in the 

 same acid ; and, when the effervescence had ceased, they had lost 

 their opacity ; the undissolved residue, unaltered in form, was 

 transparent animal matter. 



From the results of these experiments, it would appear that 

 the principal ingredients of these calculi are carbonate of lime and 

 animal matter, the former greatly preponderating. As the few 

 trials to which I considered it right to limit myself were made 

 on some of the smaller concretions, I did not attempt to ascer- 



