782 PHYSIOLOGY 



possible to demonstrate the actual presence of uric acid in the blood. In gout there 

 is constantly an increased amount of uric acid in the blood, probably in the form of 

 sodium urate, even when the patient is on a purine-free diet, so that gout may be re- 

 garded, from one point of view at any rate, as a uricsemia of endogenous origin. On 

 the other hand, the output of uric acid in the urine is not increased, and may in fact 

 be somewhat smaller than normal. It might be thought that the presence of uric 

 acid in the blood must therefore be due to diminished power of excretion of this sub- 

 stance by the kidneys. This view is difficult to reconcile with the fact that if uric 

 acid be injected subcutaneously into gouty subjects it is stated to be excreted in the 

 urine exactly in the same way and as rapidly as in normal persons. It has been 

 suggested that gout consists essentially in a disturbance in the various fermentative 

 mechanisms which are responsible for the changes undergone by the purines, so that 

 there is an increased amount not only of uric acid itself but of various intermediate 

 products in its formation from the purine bases of the food and of the tissues. The 

 deposit of the uric acid in the joint cartilages characteristic of acute gout appears to be 

 simply a crystallisation of urate of soda from a supersaturated solution of this substance 

 in the blood. The whole question of the pathology of gout and of the disordered 

 metabolism which may precede or intervene between actual acute attacks of the disease 

 is in need of further investigation. Especially is it important to determine the influence 

 on this condition not only of the nucleins and proteins of the food, but of the other 

 constituents, such as carbohydrates and fats. Speaking broadly, gout is a disease 

 of the well-to-do, of the person who, while pursuing a sedentary or no occupation, is 

 not limited in his food-supply. It is almost unknown in the labouring class, where 

 hard manual work is combined with a bare sufficiency of food. It seems therefore 

 that it is not so much the supply of purines in the diet which must be controlled as the 

 general conditions of nutrition which determine the fermentative changes in the purines, 

 either of the food or tissues, under normal conditions of metabolism. 



