152 
ON THE MICRO-ORGANISMS PRESENT IN THE ATMOSPHERE, 
Construction of plugs. — (a) Sugared glass-wool. 
(b) Sugared glass-wool and sugar-powder. 
Rate. —3'6 strokes per minute. (Tube exposed 11 ‘5 minutes.) 
[26 moulds. 
Colonies in flasks.' — (a) 42 j ^ ^ 
(b) 0. 
No. 2. Volume of air =12 litres. 
Construction of plugs. — (a) Glass-wool. 
(b) Sugared glass-wool and sugar-powder. 
Rate. —4 strokes per minute. (Tube exposed 11 minutes.) 
„ 7 . . , T , , , ^ [27 moulds. 
Colonies in flasks. — (a) 481 
J w l 0 liq. 
(b) 1. (0 mould, 0 liq.) 
Control-tube exposed 56 minutes. 
Colonies in flask. — 1 (liq.). 
St. Paul’s Churchyard. —November 19, 18S6. 4.13 p.m. to 4.25 p.m. 11 
12°-2 C. 
Volume of air = 24 litres. 
Construction of plugs. — (a) Glass-wool. 
(b) Sugared glass-wool and sugar-powder. 
Rate. —7 - 5 strokes per minute. (Tube exposed 11 minutes.) 
_ j . . n 7 , . ^ f 66 moulds. 
Colonies in flasks. — (a) 1121 
J w 1 2 liq. 
(b) 0. 
Control-tube exposed 16 minutes. 
Colonies in flask. —0. 
Summary. 
St. Raid’s Cathedral. 
Golden Gallery 
Stone Gallery . 
Churchyard 
f I. 10 colonies from 10 litres of air. 
' II. 11 
'III. 11 
| I. 35 
1 II. 41 
°T to 
