g38 GENERAL DISORDERS OF NUTRITION. 



occasion to repeat the process in the same portion of urine, after 

 they had conducted their researches for a few days. The polarizing 

 apparatus of Soleilr Ventzke is a more convenient and rapid method 

 of ascertaining the percentage of sugar in the urine. The cheaper 

 polarizing apparatus of Robiquet, though less accurate, is also appli- 

 cable to this purpose. In low grades of the malady, the quantity of 

 sugar is not more than from one to two per cent. ; in more intense 

 forms, it is as much as six or seven per cent., or more. In well-pro- 

 nounced instances, the entire amount excreted daily may exceed a 

 pound. The proportion of sugar, however, varies greatly during the 

 progress of the disease, sometimes even fluctuating perceptibly in the 

 course of a day. The causes of these fluctuations are in a great meas- 

 ure unknown, and we are acquainted with a few only of the agents 

 which are capable of increasing or diminishing the percentage of sugar 

 in the urine. Of the former, large draughts of liquid, heavy meals, 

 especially eating large quantities of sugar or of amylaceous matter ; 

 of the latter, the exclusion of sugar from the food and drink, particu- 

 larly the removal of amylaceous matter and similar glycogenous food. 

 The influence of a meal upon the percentage of sugar voided continues 

 for several hours, and then is replaced by a similar discharge of a much 

 more gradual character. Dr. Moritz Traube infers, from the great de- 

 crease in the elimination of sugar which takes place after several hours' 

 fasting, that, at a certain period during the night, there must be none 

 at all. Had Dr. Traube but tested the truth of his conclusion (and he 

 states expressly that he has not done so), had he merely examined a 

 little of this urine of the last few hours of the night, which he supposes 

 should not contain sugar, he would probably find himself to be in the 

 wrong. Among the cases under observation at my clinic, one of which 

 was of quite recent origin, affecting a young, vigorous man, still capa- 

 ble of work, and in the fourteen cases investigated by Seegen in 

 Karlsbad, the urine passed in the latter hours of the night and those 

 of early morning invariably contained sugar. Hence Dr. Traubds 

 proposed "law" is undeserving of credit until it shall have been 

 proved that cases do occur in which it is as he supposes. 



The parching thirst which distresses the patient day and night is 

 easily accounted for, as it has been proved that the polyuria of diabetes 

 is not merely a consequence of much drinking, but rather that the 

 patients drink much because they suffer an excessive loss of water 

 through the kidneys. Claude Bernard ascribes the thirst of diabetic 

 patients to the elevated temperature of the liver, which undoubtedly 

 induces an increased absorption in the intestinal canal. This hypoth- 

 esis, like the others, is idle. A diabetic patient is thirsty on account 

 of the thickening of his blood, much of whose water has been dis- 



