216 Brande oti the Medico-Chemical 



uric crust of the calculus, they would certainly injure the coats 

 of the bladder ; they would also become inactive by combination 

 with the acids of the urine, and they would form a dan- 

 gerous precipitate from the same cause. The acids, even 

 when very largely diluted, and qualified with opium, always 

 excite great irritation; they cannot, therefore, be applied 

 strong enough to dissolve any appreciable portion of the 

 stone, and the uric nucleus always remains as an ultimate 

 obstacle to success. Of the greatest difficulty in this plan 

 I have said nothing; namely, the ascertaining the nature 

 of the surface of the stone that is to be acted upon ; for ad- 

 mitting this to be known, the above objections and the necessity 

 of the very frequent introduction of an instrument into the 

 highly irritable bladder, are obstacles which I cannot regard as 

 surmountable. It therefore appears to me, that Fourcroy, and 

 others who have advised the plan of injection, have thought little 

 of all these obstacles to success, and have regarded the bladder 

 as a lifeless receptacle into which, as into an India rubber bottle, 

 almost any solvent might be injected with impunity. 



Having shewn the extreme improbability of even a small 

 calculus being dissolved in the bladder, it only remains to 

 notice those cases of supposed solution which have given cele- 

 brity to certain remedies ; or, in other words, to mention 

 those causes which tend to annihilate the ordinary symptoms 

 of calculus, though the concretion still remains in the bladder. 



Sir Everard Home, in his observations above quoted, has 

 furnished some valuable illustrative cases on this head ; and has 

 particularly noticed two, " because they were published during 

 the patie7it's life-time, in proof of the stone being dissolved." 

 These patients had both suffered from the disease many years, 

 but when they attained the age of about 68, the symptoms entirely 

 left them. In one of these cases twenty calculi were found in 

 the bladder after death, and the cause of the disappearance of 

 the symptoms was found in the enlargement of the posterior lobe 

 of the prostate gland, which, forming a barrier between the 

 calculi and the orifice of the bladder, kept the calculi in its 

 lower posterior part, where they lay without producing disturb- 



