281 



alteration of pitch by conduction is that by Dr. Walshe*, who 

 ascribes it to transmission of the vibrations through "varying" 

 media. 



II. " On the frequent occurrence of Phosphate of Lime, in the 

 crystalline form, in Human Urine, and on its pathological 

 importance." By ARTHUR HILL HASSALL, M.D. Lond. 

 Communicated by Dr. SHARPEY, Sec. R.S. Received 

 November 9, 1859. 



In 1854 I submitted to the Royal Society a paper "On the 

 frequent occurrence of Indigo in Human Urine." This communi- 

 cation, which was published in the ' Philosophical Transactions,' 

 attracted considerable attention both at home and abroad. The 

 singular fact of the frequent presence of indigo in the urine, first 

 announced by me, has since been amply confirmed by a variety of 

 observers. I have now to place before the Society some investiga- 

 tions in relation to the not uncommon occurrence in human urine of 

 phosphate of lime, as a deposit, in a well-marked crystalline form. 



When the earthy phosphates are treated of by writers, in con- 

 nexion with the urine, they are usually described collectively, and it 

 is seldom that each kind of phosphate is particularized, and yet there 

 are several which may occur either separately or together. The 

 phosphate of ammonia and magnesia, or triple phosphate, is indeed 

 often specified, but rarely is phosphate of lime separately mentioned, 

 and phosphate of magnesia scarcely ever ; and yet phosphate of lime 

 is very frequently present as a deposit in urine, much more so, indeed, 

 according to my experience, than the triple phosphate, excluding 

 those cases of the occurrence of that ammoniacal phosphate, arising 

 from the decomposition of the urea of the urine subsequent to its 

 escape from the kidneys. Even in those few cases in which phosphate 

 of lime is specially mentioned, it is described usually as mixed up 

 with the other phosphates, and always as occurring in the amorphous 

 or granular, and never in the crystalline state ; further, no peculiar 

 importance is attached to it, as contrasted with the magnesian phos- 

 phate. 



* Disease of the Lungs, Heart, and Aorta. 2nd edition, page 151. 



