ORGANIC MATTER OF HUMAN BREATH. 243 



in use in the establishment. The plates were afterwards 

 carefully searched with the microscope ; but at that time I 

 could recognize little except fibres of cotton and wool, 

 and shrivelled epithelial scales : there were also some 

 singular-looking bodies; but these, I found afterwards, 

 were contained in the glycerine used to cover the slips of 

 glass. 



Upon another occasion, during a crowded lecture at 

 the Free-Trade Hall, about 3000 persons being present, 



1 drew the air from one of the private boxes (raised about 

 40 feet above the audience) by means of exhausting bel- 

 lows, through a system of narrow tubes filled with distilled 

 water, the operation being conducted for a space of about 



2 hours. The water was emptied from the tubes, allowed 

 to settle for 36 hours, and the sediment was examined 

 microscopically. The following objects were noted at the 

 time, and sketched under the microscope, the i-inch 

 power being used : — fibres, separate little cellules, nucleated 

 cells surrounded by granular matter (about 6 in i drop 

 of water), numerous scales like degenerated epithelial 

 scales. 



The dust from the top of one of the pillars in the private 

 boxes, which had not been disturbed for 3 weeks, was also 

 examined shortly afterwards, and the following objects 

 were noted as being present : — 



1. A few fibres of cotton and wool. 



2. Black masses of various shapes and sizes, which were 

 taken to be specks of coal-dust. 



3. Semitransparent little lumps, refracting light strongly. 



4. Crystalline substances, having a laminated texture 

 (query, fragments of glass ?) . 



5. Shrivelled pieces of membrane, epithelial scales. 



6. Collections of granules. 



7. Variously coloured fragments, blue, pink, and yellow, 

 probably portions of dress. 



r2 



