324 DIABETES MELLITUS. 



Feasible, however, as this or any other hypothesis may 

 appear, it must never be forgotten that conclusions arrived at 

 from post-mortem experiments may, when tested by ante- 

 mortem teaching, require much modification. In the develop- 

 ment of this disease it is highly probable that other and im- 

 portant changes have preceded the appearance of what is 

 generally looked upon as the most characteristic symptom of 

 diabetes — saccharine urine — that this is merely a confirmation 

 of the disease, a passing into the second stage of the morbid 

 process. 



Symptoms. — The increased secretion of urine, with accom- 

 panying thirst, are here, as in the already described form, 

 prominent symptoms ; they may not, however, if the case has 

 been carefully watched, be the earliest, which in all likelihood 

 are such as indicate simply defective digestion and want of 

 general vigour. In all cases of largely augmented urinary 

 secretion, with general disturbance, attention ought at once to 

 be directed to the character of the secretion ; should this be 

 found to be of increased density other tests ought at once to 

 be resorted to, so as to ascertain whether or not sugar is 

 present. 



In addition to its increased specific gravity, fragrant smeU, 

 and sweetish taste, diabetic urine, in certain cases where the 

 quantity of sugar is excessive, will be found, when allowed to 

 remain at rest for some hours in appropriate vessels, to yield a 

 deposit of needle-like, prismatic-shaped crystals of grape-sugar. 

 The indications arrived at by attention to any of these condi- 

 tions being only approximate, definite results are attained 

 chiefly through the employment of two chemical tests, one 

 depending on the reaction of the salts of copper, known as 

 ' Tromer's test ;' the other upon the development of the vinous 

 fermentation of the sugar and evolution of carbonic acid, and 

 recognised by the name of the ' fermentation test.' 



In employing Tromer's test a small portion of the suspected 

 urine is placed in a test-tube ; to this is added a few di'ops of 

 sulphate of copper solution, sufficient to give the liquid a 

 slight blue colour. Solution of potash is now added, in quantity 

 from one-half to as much as the urine employed ; this will 

 throw down a pale-blue precipitate of the hydrated oxide of 

 copper, which, if there is sugar present, will rapidly redissolve 



