METABOLISM IN NEPHRITIS 353 



medical standpoint the test is a rough quantitative measure of the total 

 kidney function whatever that may be; I do not think that we are in a 

 position at the present time to say what is the total kidney function." 



Clinical Value, The worth of the phthalein test has been established 

 by too numerous observations for individual mention. The normal excre- 

 tion of the drug in two hours after the intramuscular injection is 60 per 

 cent ; diminishing values to zero may be found ; life is compatible with 

 no elimination of phthalein whatsoever, though the outlook is always 

 serious under the circumstances (the author has, noted one case in which 

 life was maintained for a period of two and one-half years though re- 

 peated tests during that time showed that no phthalein or only traces would 

 be present in the urine) . Usually any figure of twenty per cent or less may 

 be regarded to be of serious omen. 



In certain conditions in which the kidney may be considered as being 

 "irritated" or overactive, there is a distinct elimination of phthalein above 

 the normal. Lewis has shown how this phenomenon occurs in early chronic 

 diffuse nephritis, fever, hyperthyroidism, and in some cases of hyperten- 

 sion. Such a supernormal" phthalein figures are accompanied by similar 

 findings in the urea excretion. These facts will be discussed in detail 

 under the heading of the coefficient of urea excretion. 



In nearly all forms of nephritis apparently the idea of Marshall 

 and Kolls that the amount of phthalein eliminated depends upon the 

 amount of actively functionating kidney substance seems to hold true. 

 There is one form of nephritis, the so-called parenchymatous (character- 

 ized by albuminuria, diminished salt excretion and edema), in which the 

 phthalein may be put out not only in normal amounts but even in still 

 larger quantities. Thus Pepper and Austin (a) report one such case in 

 which as much as 82 per cent was found in two hours, and Baetjer, four 

 cases with outputs varying from G9 to 90 per cent. These findings and 

 those mentioned in the preceding paragraph are reminders of the fact that 

 nephritis is a disease whose severity in some instances can not be measured 

 by renal function alone. 



Tests for Function of the Glomeruli and Tubules 



The idea of correlating clinical signs, symptoms and tests with patho- 

 logical changes in the kidney has been an alluring goal for a long time. 

 Many researches have shown the futility of solving this problem satisfac- 

 torily. It is doubtful whether this can ever be accomplished because any 

 renal functional test reflects not only the state of the kidney, but that oi 

 the whole body. Cardiac influences, disturbances of the nervous system, 

 abnormal water metabolism, pathological conditions of the ureter and blad- 

 der, etc., give pictures of abnormal renal function which can not be dis- 

 tinguished from those whose cause resides solely in the kidney. 



