ON THE STRUCTURE OF CALCULI. 53 



It is a circumstance deserving notice, that in the case, Mrs. Stevens, 

 which gave celebrity to Mrs. Stevens's medicine, and procur- 

 ed her a remuneration from Parliament, the bladder was 

 not examined after death. 



That calculi in the bladder do sometimes increase, while Calculi some- 

 the patient is using alkaline medicines, is fully proved by d ™J^ » the ass 

 the following examples, which also show, that the uric acid of alkalis, 

 and phosphates are formed in different proportions, accord- 

 ing to the peculiarities of the constitution. 



A gentleman who suffered from symptoms of stone was founceofthis. 

 sounded, and a stone was found in his bladder. I put him 

 on a course of alkaline medicines, and he voided a small 

 compact calculus, composed of uric acid, and evidently 

 formed in the kidney. He wa6 desired to persist in the use 

 of the medicines, which he did at intervals for four or five 

 years, suffering occasionally in a slight degree, but he did 

 not pass any more calculi. He died at the age of seventy- 

 five. On examining the bladder, its whole cavity, (the ca- 

 pacity of which was equal to a pint measure) was completely 

 filled with soft, light, spongy calculi, three hundred and fifty 

 in number, and of different sizes, from that of a walnut to a 

 small pea. They were composed of a mixture of uric acid 

 in powder, the phosphates, and animal mucus; and differed 

 so much from the calculus voided soon after the patient be- 

 gun the use of alkalis, that they appear to have been form- 

 ed after that period in the manner mentioned by Mr. W. 

 Brande. 



A gentleman, who was found to have a stone in his blad- Another, 

 der, was persuaded, that it was so small, that it might be 

 dissolved, and with this view he took the fossil alkali, both 

 in its caustic and mild state, for about three months ; but at 

 the end of that period the symptoms were increased, and he 

 submitted to have it extracted by an operation. On ex- 

 amining the calculus after it was extracted, the external 

 part, for the thickness of T V of an inch, was entirely com- 

 posed of triple phosphate, in a state of perfect spiculated 

 crystals, so as to present a very rough irritating surface to 

 the internal membrane of the bladder, while the inner parts 

 of the calculus were made up of a mixture of uric acid and 

 phosphates, so that the alkali had prevented, the formation 



of 



