50 High Operation for the Stone. 



to see the urine, as I had never before known this salt deposited 

 alone from that secretion, and hence had been led to believe that 

 calculi composed entirely of that substance were not of urinary 

 origin, but formed in a manner analogous to those met with in the 

 prostate gland. 



The specimens of urine which you were good enough to send 

 me arrived in safety, but I am sorry to say that they throw no 

 light on the subj&ct, or rather on the point in question. They 

 are alkaline, and of a very bad character, and abound in the 

 mixed phosphates, (that is, the phosphate of lime and the triple 

 phosphate of magnesia and ammonia,) as is usual in such 

 cases. 



I am, my dear Sir, 



Yours, &c. much obliged. 

 W. Prout. 

 40, Sackville- Street. 



Art. VIIL On Calcareous Cements. By 



John White, Esq. 



j 



[Communicated by the Author.] 

 To the Editor of the Quarterly Journal. 

 Sir, 



In the Miscellaneous Intelligence contained in your last number, 

 you have remarked, that you should take notice of such facts 

 respecting the theory and improvement of calcareous cements as 

 were brought to light at different times, with the fair conclusions 

 to be drawn from them, being convinced, in the highest degree, of 

 the importance of the subject, and of the advantage which the 

 investigation must lead to, 



Having for nearly thirty years experienced, practically, the im- 

 perfections of the various cements in use in England, I have been 

 led into a variety of examinations of them, and do not hesitate to 

 communicate to you an account of a series of experiments which 



