56 SELLARDS AND SHAKLEE. 



As regards tlie increased excretion of ammonia in the urine, we have 

 observed that occassionally the injection of rather large amounts of alkali 

 does not reduce the ammonia out-put. A similar result may also occur 

 in diabetes. (3) 



Suppression of urea. — The first specimens of urine voided after a 

 period of anuria are often found to contain subnormal amounts of urea. 

 If the test is made with sodium hypobromite, it also shows that the 

 content of ammonium salts as well may be relatively low in the first 

 specimens. The explanations which suggest themselves may be con- 

 sidered under the two general heads, i. e. there may either be retention 

 of urea by the organism or there may be a diminished production. In 

 cases where there is suppression of urine, an acute nephritis is always 

 present and one must consider the possibility of retention of urea on 

 account of the kidney lesion. On the other hand, the nitrogen whicli 

 is ordinarily transferred to the production of urea,- might be diverted 

 for the neutralization of acids. Lastly, a diminished production of 

 urea might result from an impairment in the function of the urea- 

 forming organs. A few data have been collected which have some bear- 

 ing on these ppssible explanations. 



Excretion of urea by the kidneys. — The possibility of retention of 

 urea in the body was first considered. No determinations were made 

 with the purpose of detecting an accumulation of urea in the blood 

 or other tissues. Instead of this, urea was injected intravenously into 

 patients who showed a well-marked suppression of urea, the object 

 being to determine whether the lesions of the kidney were sufficient 

 to prevent the excretion of urea, provided it were present in the blood. 

 Previous determinations had shown that, in patients treated with so- 

 dium chloride, the urea, after a period of partial suppression, returns 

 very gradually to normal. Only a limited number of cases were tested. 

 In order to avoid a sudden spontaneous increase in the urea excre- 

 tion, very severe cases were selected in which recovery, if it occurred 

 at all, would be relatively slow. The urea in solid form was added 

 directly to two liters of Ringer's solution and in every instance the 

 injection was made intravenously. Eelatively small amounts of urea 

 were employed, the maximum being 10 grams. All of the cases showed 

 a very acute nephritis in addition to the suppression of urea. The 

 severity of the cases selected made it improbable that any spontaneous 

 increase in the excretion of urea would take place. Four cases were 

 obtained which were suitable for injection. The protocols are as fol- 

 lows: 



The first patient (number 4) was admitted in partial collapse. During the 

 first thirty hours in the hospital he received three intravenous injections of 2 



