28 SUGAR IN URINE. 



Sugar occurs in the urine of man, in a lingering and very 

 fatal disease called ' diabetes mellitus/ This disease is cha- 

 racterised by the excretion of very much increased quantities 

 of urine, and by the presence hi the urine of large quantities 

 of sugar. Although the lower animals often suffer from what 

 is called ' diabetes insipidus/ viz., pass an abnormal quantity 

 of urine, it has rarely been known to contain sugar. 



Dr Watson, in the second volume (page 648) of his ad- 

 mirable treatise, " On the Principles and Practice of Physic/' 

 tells us that he once had a coach-horse which he thought 

 might have diabetes : " He was a greedy feeder and drank 

 eagerly/' says Dr Watson, " yet he grew thinner and thinner ; 

 and at whatever door I had occasion to stop, there he invari- 

 ably began to stale, so that I became thoroughly ashamed of 

 his leaking. Dr Prout was good enough to examine the 

 urine for me. It contained no sugar, but its healthy proper- 

 ties were much changed. It had less than the natural quan- 

 tity of hippuric acid, and more of earthy matter." 



As there is no reason why the lower animals should not be 

 subject to diabetes, and as their urine has been only rarely 

 examined, I think it right to describe the way in which 

 sugar may be detected in urine. In the first place, though 

 the amount of urine is very large, its specific gravity is very 

 high in diabetes. When some urine containing sugar is 

 boiled in a test tube with a little solution of potassa (liquor 

 potassae), it assumes a brown colour, often nearly approaching 

 that of claret. 



The best test is, however, that which is known by the 



and have not yet been confirmed, we shall not describe the application 

 of Pettenkoffer's test, referring our readers to Dr Barley's original 

 paper, read before the last meeting (1862) of the British Medical 

 Association, and a notice of which appeared in all the weekly medical 

 journal*. 



