METABOLISM IN FEVER AND CERTAIN INFECTIONS 127 



other fevers show a similar high excretion of nitrogen for several days 

 after a fall in temperature. 



Lanz gives a series of six cases in which he determined the daily loss 

 of nitrogen in the sputum. The figures are about the same as in tubercu- 

 losis, ranging from 0.3 to 1.7 gm. per day. In bronchitis the nitrogen 

 loss was about half this, in gangrene of the lung it reached as high as 2.5 

 gm. on one day. 



Chlorid Metabolism. The excretion of chlorids is diminished in 

 almost all fevers, malaria being a notable exception, but the diminution is 

 most striking in pneumonia. There may even be a complete disappearance 

 of chlorids from the urine for several davs. The chloride-poor fever diet, 

 consisting chiefly of milk, would naturally cause some diminution, but the 

 chlorids remain low even if they are given in large amounts in the food. 

 The pneumonic exudate, according to Hutchinson, will account for only 

 one-third or one-half of the total amount retained. 



Terray(a.), one of the earlier investigators of the subject, studied the 

 chlorids in five pneumonia patients and found retention which increased 

 up to the crisis and then less retention for a few days. After the eleventh 

 day there was a -negative chlorid balance. Terray believed the retention 

 of sodium chlorid was associated with water retention. 



Peabody(&) has made some analyses of the chlorin in the solidified 

 lungs as compared with the normal lungs. 



Practically all of the observers who have made blood analyses have 

 found low chlorids in the blood serum. This conflicted with the theory 

 that the kidney was responsible for the retention. All doubts have been 

 removed by Snapper (a) and more recently by McLean (&). The former 

 found in five pneumonia patients figures for NaCl in the serum between 

 5.40 and 5.60 gm. per liter, all below his normal "threshold" value of 5.60, 

 which corresponds closely with Ambard's figure of 5.62. He points out that 

 under such conditions one would not expect the normal kidney to excrete 

 chlorids. In the one case where the serum chlorids were above the 

 "threshold" the salt was excreted according to the formula that Snapper 

 found in normal cases. McLean made sixty analyses in thirteen cases of 

 pneumonia and found that the plasma NaCl was almost below 5.62 gm. 

 per liter, the normal threshold. He found that in fever the threshold 

 was even depressed to about 5.42. At the time when the concentration 

 of salt in the serum increased the excretion through the kidney was re- 



