AND ITS EFFECTS UPON ANIMAL LIFE. 1 3 



again cooled by conducting it through a cylinder .surrounded witli ice. In this 

 manner all moisture contained in the air was condensed. From this cylinder the 

 air passed through a series of twelve U-tubes, each made from a piece of tubing 

 80 cm. in length and of '_' niillimetei's internal diametei'. During its passage 

 through these U-tubes the air assumed a temperatui'e of about 18 " C. as it entered 

 the fourth flask. Tlie results obtained by this arrangement substantiated the con- 

 clusions they had formed from conducting the experiment in the ordinary manner, 

 that the cause of death was traceable to the high per cent, of carbonic acid. The 

 removal of the organic matter by combustion failed to save the life of the animal 

 in the last jar when the carbonic acid had increased to 11 or '['2 per cent. After 

 the absorption of the carbonic acid by means of soda-lime the last animal remained 

 alive. They conclude, thei'efore, that the poisonous expiratory jioison of Brown- 

 Setpiard and d'Arsonval does not exist, but that death is produced by the excess 

 of carbonic acid in the flasks. 



Brown-Sequard and d'Arsonval, in 1894, (35), reported further experiments, and 

 at the same time gave fuller details as to all their experiments and the apparatus em- 

 plo^-ed. They had inoculated over onehundredanimals with the condensed fluid of 

 respiration and believed in the truth of their former statements as firmly as ever. 

 They could not understand the failures on the part of the other expei'imenters. 

 They emphaticall}^ reaffirm that the expired breath of man and animals contains a 

 volatile organic poison producing the results reported by them, and that these 

 results are not produced by excess of carbonic acid or deficiency of oxygen in 

 the ail'. 



Fi'om the foregoing summary of the reports of different experimentei's, it will be 

 seen that widely different results have been reported by them, but that the majority 

 of the later investigators agree in denying that the exhaled breath of healthy- 

 human beings or of animals contains a poisonous organic alkaloid, or any poisonous 

 product other than carbonic acid, yet in any case positive results require an expla- 

 nation which shall account for the facts. 



DE. BERGEy's ESPEEIMENTS. 



The first experiments made by Dr. Bergey were to ascertain whether the con- 

 densed moisture of air expired by men in ordinary, quiet respiration, contains any 

 particulate organic matters, such as micro-organisms, epithelial scales, etc. The 

 test for micro-organisms was made by having an adult man expire for from twenty 

 to thirty minutes through sterilized melted gelatin, which was then preserved as a 

 culture for from twenty to thirty days. In the first trial, six, and in the second 



