THE COMPOSITION OF EXPIRED AIR. 405 



were made into the general circulation in rabbits, and into the peri- 

 toneal cavities of rabbits, guinea pigs, and white rats, following the 

 methods employed by Brown-Sequard and d'Arsonval and by V. Hof- 

 mann-Wellenhof. The fluid was collected with the greatest care in a 

 sterilized apparatus; subsequent cultures made from it indicating that 

 it was sterile. It was warmed to about 35° C. before injection. The 

 proportion injected, as compared with the body weight of the animals, 

 was, in some instances, less than that used by Brown-Sequard and 

 d'Arsonval, in others greater than the smallest quantities used by them 

 with fatal effects. 



In most of the animals no observable disturbance of health was pro- 

 duced, nor did this condition alter in the course of several months 

 during which they were kept under observation. One rabbit died 

 thirty-two days after having received an injection into its peritoneal 

 cavity of 5 c. c. of fluid condensed from the breath of a man with tra- 

 cheal fistula. The results of post-mortem examination showed focal 

 necrosis in the liver, but no ecchymoses and hemorrhages in the lungs 

 and intestines, such as are reported as a characteristic result of such 

 injections by Brown Sequard and d'Arsonval. Three other rabbits 

 which had received injections of the condensed fluid, and had remained 

 apparently perfectly well from six weeks to seven months, were killed 

 and careful post-mortem examinations made. The results of these 

 examinations showed that there was no special disease or degeneration 

 ill the organs of these animals. 



The results of this series of experiments are, therefore, in accord 

 with those reported by V. Hofmann- Wellenhof, and indicate that fluid 

 condensed from the pulmonary exhalations of man has no toxic or 

 specially injurious effect when injected into animals, and that there is 

 no evidence that such fluid contains an organic poison. 



The attempt to collect condensed moisture from the air of the hospital 

 ward was but partially successful, as has been stated above, and a suf- 

 ficient amount of the fluid to make injection experiments was not 

 directly obtained. To overcome this difficulty, the air of the ward was 

 drawn over sterilized glycerin, which was then diluted with distilled 

 water, and the product injected into animals. Three of the animals 

 thus injected died between four and six weeks later, but the post-mortem 

 examinations failed to show any clear connection between the injection 

 and the fatal result. As it was shown that the fluid collected and that 

 the dust in the ward contained several species of bacteria, including 

 pathogenic forms, it was to be expected that more definite results would 

 have been obtained, but the power of the cells and tissues to resist the 

 pathogenic organisms was sufficient to prevent their action in each case, 

 except, perhaps, in one, in which the abscess produced may have been 

 due to pyogenic bacteria in the injected fluid. 



A number of experiments were made in which animals, in a series of 

 bell jars, were caused to breathe air which became more contaminated 



