1820.] Dr. Henry onUnmry Calaili. 113 



and examples of the latter kind have been related by Dr. Heber- 

 den and Sir Everard Home. 



Two instances have fallen within my knowledge, in which 

 persons have voided quantities of uric acid with the urine, far 

 • exceeding any thing that I can find upon record. In the first, 

 which was mentioned to me by Professor Monro, of Edinburgh, 

 every pint of the urine voided by a man about 40 years of age, 

 who laboured under symptoms of gravel, deposited about two 

 ounces of a brick-coloured sediment, which I found on examina- 

 tion to be chiefly uric acid with a very small relative proportion 

 of the earthy phosphates. In another instance, a lady of middle 

 age, who was subject to gravel, was in the habit, when warned of 

 its approach by ths usual symptoms, of having recourse to a 

 medicine, the composition of which is kept secret, but which 

 appears to me to be nothing more than spirit of turpentine 

 coloured by a little petroleum, with the addition of a portion of 

 tincture of opium. The uniform effect of this medicine was the 

 discharge of a sandy substance in such quantity that more than 

 four ounces were sometimes voided within the space of two or 

 three days. It was composed chiefly of uric acid, with a small 

 proportion of urea and of the earthy phosphates. I have since 

 known another instance in which the same medicine has produced 

 a similar effect, though not to an equal extent, proljably by acting 

 as a stimulant to the kidneys, and clearing them by the increased 

 flow of urine which it excites of the sand that had been depo- 

 sited in the tubuli uriniferi and pelves of those organs. 



Calculi composed chiejiy of the Earthy Phosphates. 



The pure phosphate of Hme, or bone earth calculus, I have not 

 been able to recognize in any of the collections of calculi which 

 I have examined, though assisted by a recollection suffi- 

 ciently distinct of one which was shown to me some years 

 ago by Dr. Wollaston ; nor have I ever found the triple phos- 

 phate of ammonia and magnesia composing, in a pure state, an 

 entire calculus, though in Mr. White's collection there is one 

 containing more than 90 per cent, of that salt. From this pro- 

 portion I have found it in a variety of others, down to 20 and 

 even 10 per cent. With phosphate of lime, in proportions which 

 seem to have a considerable range, it constitutes the fusible 

 calculus, and this mixture forms the principal ingredient of 

 calculi that have concreted round foreign substances. A calculus 

 in Mr. White's collection, the nucleus of which is a bougie that 

 had slipped into the bladder, is composed of 



Phosphate of lime 20 



Ammoniaco-magn. phosph 60 



Uric acid 10 



. Animal matter , 10 



Too 



Vol. XV. N° II. H 



