Mr. T. Taylor on a new Species ofBiliai*y Calculus. 13 



The greater part of the loss in this analysis should be 

 added to the stearic acid, as owing to the sudden extrica- 

 tion of vapour while under the receiver of the air-pump a 

 small part of the acid was thrown out; but I prefer giving 

 the quantities actually obtained to making any allowance for 

 known sources of error. 



The composition of the calculus clearly points out its biliary 

 origin, but whether taken from man or the brute must remain 

 doubtful, as there is no history to guide us. 



Stearic, margaric, and oleic acids exist in the bile of oxen 

 in combination with soda ; and according to Lecanu and Casa- 

 seca*, stearic and oleic acid in that of man ; the latter I have 

 frequently detected, but I cannot find that these acids have 

 ever been noticed as entering into the composition of biliary 

 concretions, much less forming the prominent constituent. I 

 was unable to detect the slightest trace of these acids in five 

 specimens selected from about 200. 



From cholesterine calculi it is readily distinguished by the 

 absence of any crystalline structure when broken, which un- 

 less the quantity of colouring matter be very large is always 

 more or less apparent in that variety ; also by its insolubility 

 in alcohol or aether and by readily dissolving in these men- 

 strua, and in a cold solution of caustic potass after it has 

 been acted upon by an acid. 



Before I conclude, I am anxious to rectify an error which 

 I inadvertently committed in my paper on the calculi in the 

 museum of St. Bartholomew's Hospital f. I there stated that 

 urate of ammonia had always been confounded with the 

 uric acid variety in the tables that had been published on 

 the relative frequency of the different species of calculus^:. 

 This was not, however, the case in a paper by Dr. Yelloly, 

 in the Philosophical Transactions for 1829-30, containing 

 the analysis of the Norwich collection, and I regret that I 

 have not had an opportunity of making this acknowlegement 

 sooner. 



April 8th, 1840, THOMAS TAYLOR, 



New Bridge Street, London. M.R.C.S. 



N.B. A notice of this calculus was sent to the Board of 

 Curators in March 1839, but a variety of circumstances have 

 delayed its publication. 



* Gmelin's Handbuchdcr Chcmie: Journal de P/tarmacie, 12. 



f L. & E. Phil. Mag. vol. xii. p. 412. j Zl>. p. 414. 



