APPENDIX. 



Details of methods employed, and results obtained, in experiments upon- the 



effects of expired air. 



David Hendricks Bergey, B. S., M. D. 



(The numbers in parentheses refer to the bibliographical list appended to the report.) 



I. — Four experiments were made to determine whether the air expired by man contains micro- 

 organisms. The results are shown in the following table. 



Table A. 



In these experiments the expired breath was conducted through melted gelatin contained in the 

 apparatus shown in Fig. i, for 20 to 30 minutes. The gelatin was then hardened by rolling the flask 

 in a shallow basin containing ice-water, thus distributing the culture in a thin layer over the bottom 



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