406 PROCESSES INFERRED FROM DIRECT OBSERVATION 



have shown that a large part of the glucose which circulates in the 

 blood of a diabetic is actually utilized by his tissues. 



The examination of the blood in diabetics very frequently reveals, 

 not only glucohemia, but also a pronounced Lipemia, which may be so 

 severe as to give to the centrifuged blood-serum a distinctly milky 

 appearance. The following are results obtained by Bloor in estimating 

 the lipoids in normal and in diabetic blood : 



It will be observed that the percentage of all the lipoidal constituents 

 of the plasma is much increased in diabetics, while the lipoidal con- 

 stituents of the corpuscles remain comparatively unaffected. The 

 increase is especially marked in the Neutral Fats (estimated as fatty 

 acids) and in the Cholesterol fractions. The lecithin or Phospholipin 

 fraction increases also but in much less proportion than the others, so 



. fatty acid cholesterol 



that the ratios : r-p or = T-T-. are abnormally high in 

 lecithin lecithin 



diabetic blood-plasma. For this reason it has been suggested that part 

 at least of the failure of diabetics to utilize fat is due to an inability 

 to convert neutral fatty acids into phospholipins. 



The attention of earlier investigators of diabetes was focussed upon 

 the intolerance of these patients for carbohydrates, and the main 

 objective of the physician was to decrease the output of glucose in the 

 urine. Carbohydrates were therefore necessarily excluded from the 

 diet, and to replace the deficient calorific value thus entailed the fats 

 in the diet were not unusually increased. This procedure frequently 

 had the gratifying result, for the time being, of reducing or even elimi- 

 nating the output of glucose in the urine, but sooner or later the patient, 

 whose condition at first seemed much improved, would again begin to 

 excrete glucose; a severe acidosis developed and the case became hope- 

 less, terminating in diabetic coma. 



This result has been duplicated by F. M. Allen in partially depan- 

 creatized dogs, and he attributes it to the progressive degeneration of 

 the Islets of Langerhans in the residual tissue due to overstrain. As a 

 source of protein he administered beef-lung to the animals, and suet 

 was employed as a means of administering fats. The following is his 

 description of a typical result : 



"We may take the customary treatment of moderate diabetes and 



