32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



respiration no bacteria, epithelial scales, or particles of dead tissue 

 are exhaled. 



Fliigge has shown that in the act of coughing, sneezing, or speak- 

 ing, such organisms or particles may be thrown out (droplet con- 

 tagion). The minute quantity of ammonia or other oxidizable 

 matter in the condensed moisture of human breath appears to be 

 due to the decomposition of organic matter in the mouth and 

 pharynx. Thus the reducing power is greater 4 hours after eating 

 than y 2 hour after, and far less if the mouth is cleansed ; for example, 

 equivalent to 12 milligrams of 2 per liter against 3 milligrams. 

 Experiments on the air of the hospital ward, and the moisture con- 

 densed therefrom, showed that the greater part of the ammonia is 

 connected with dust particles, microorganisms, etc., which can be 

 filtered off. The bacteria are probably the only really dangerous 

 elements in the air. 



The fluid condensed from the pulmonary exhalations of man has 

 no toxic or specially injurious effect when injected into animals, 

 and there is no evidence that such fluid contains an organic poison. 

 The fluid was collected with great care in sterilized apparatus, and 

 was proved to be sterile ; it was warmed to body temperature, and 

 was injected in doses in some instances less, in others greater, than 

 the smallest quantities which were used by Brown-Sequard and 

 D'Arsonval with fatal effects. 



Peters tested the condensation fluid obtained from human breath 

 on the frog's heart. It had no poisonous effect. In the last year or 

 two Weichardt 1 claims to have found traces of "kenotoxin" in 

 expired air. This, he says, is a protein decomposition product of 

 high molecular weight obtainable in the juice expressed from 

 fatigued muscles. He obtained the condensation fluid from the 

 expired air of a fatigued man of 60 years who breathed through 

 wadding for 2 hours. The fluid was expressed from the wadding. 

 He claims to have obtained it also from blotting paper exposed in 

 a room crowded with sleepers. The fluid was concentrated by 

 evaporation and 1 cc. or more was injected into a mous*e. 



Inaba 2 carried out similar experiments and reached the conclusion 

 that the mice were poisoned no less by an equally large dose of dis- 

 tilled water. Thus 0.3 to 0.7 cc. gave no result, while 1 to 1.5 cc. 

 made the mice ill. So, too, with distilled water; to put 1 or 1.5 cc. 

 of water into a 13-gram mouse is the same as injecting 5 liters into 

 a oo-kilocram man. 



1 Arch. f. Hygiene, Vol. 74, p. 185, [911. 

 8 Ztschr. f. Hygiene, Vol. 68, p. I, 101 1. 



