THE COMPOSITION OF EXPIRED AIR. 



401 



tuberculosis of the luugs. In each case the amount of ammonia and of 

 albuminoid ammonia in the fluid was very small, the average being, iu 

 grams per liter of fluid : 



Healthy man 



Man with tracheal fistula 

 Consumptive . . 



Free am- 

 monia. 



0.019 

 . 00046 



.003 



Albuminoid 

 ammonia. 



0.081 



. ooo:;g 



.0034 



The oxidizable matter in these fluids, as shown by their reducing 

 power on a solution of permanganate of potash, was determined. The 

 average results, stated in milligrams of oxygen consumed per liter of 

 condensed fluid, are as follows : Healthy man, 10.72 ; man with tracheal 

 fistula, 13.49; consumptive, 19.34. The high average for the man with 

 the tracheal fistula is due to a single observation, for which the figure 

 was 24.916. Omitting this, the average for the three other observations 

 would be 9.08. 



The average for five specimens of fluid condensed from the expired 

 air of a healthy man four hours after he had taken a meal was 11.98, 

 while the average for six specimens from the breath of the same man 

 half an hour after the meal was only 3.86. For two specimens from the 

 same man collected three and a half and four hours after a meal, but 

 just after the mouth had been thoroughly rinsed with warm water, the 

 average was 2.49. These results indicate that the ammonia and oxi 

 dizable organic matter in the condensed fluid were, to a large extent, 

 due to products of decomposition of organic matters in the mouth. The 

 well-known fact that the amount of oxygen absorbed and of carbonic 

 acid given off varies according to whether the person is fasting or has 

 recently taken a meal, may possibly be in part due to the same cause, 

 but the results obtained by Birkkolz (31) indicate that it can only be 

 in part. Ransome (8) reports no marked difference in the amount of 

 ammonia, or of oxidizable organic matter, as determined by the per- 

 manganate test, contained in the fluids collected from the exhaled 

 breath soon after a meal and in that collected from a fasting person. 

 Beu (25) found a much higher proportion of oxidizable matter in the 

 fluid condensed from his own breath (50 milligrams of oxygen required 

 per liter of fluid) than was found in Dr. Bergey's experiments. His 

 results indicated the exhalation of 15 milligrams of organic matter in 

 twenty-four hours, the corresponding figure from Bansome's results 

 being 20 milligrams. About 12 c. c. of fluid was collected from about 

 335 liters of air expired j>er hour, being nearly equal to the results 

 obtained by Beu (25), who condensed 100 c. c. of the fluid from 3 cubic 

 meters of air expired in eight hours. 



Renk (32, p. 162) gives a table showing that in an average quantity 

 of 9,000 liters of air expired in a day by a healthy man, the amount of 

 moisture may be from 200 to 400 grams, depending on the temperature 

 Sm 95 26 



