THE MICRO-ORGANISMS PRESENT IN THE ATMOSPHERE. 
147 
0 ]iq. 
Rate. —5‘7 strokes per minute. (Tube exposed 13 minutes.) 
, . f 20 moulds. 
Colonies in flasks .—(«) 431 
(b) 0. 
Control-tube , containing plug of sugared glass-wool, exposed 48 minutes. 
0 moulds. 
0 liq. 
No. 1 (glass-wool), 21 colonies. 
Colonies in flask, 1 
10 litres of air yielded, therefore, in 
No. 2 (sugar-wool), 24 
No. 3. Hesse’s method. 
Volume of air =10 litres. 
Colonies in tube . . .68 
,, control-tube 17* 
25 moulds. 
0 liq. 
3 moulds. 
1 liq. 
IX. Chemical Laboratory (private). October 27, 1886. Windows and door closed ; 
3 persons in room, but not moving about. 10.59 A.M. to 11.54 A.M. 16°'9 C. 
Nos. 1 and 2. Flask method .—(Double plugs.) 
No. 3. Hesse’s method. 
Nos. 1 and 2 alternated in aspiration; No. 3 aspirated simultaneously in 
close proximity. 
No. 1. Flask method. 
Volume of air =18 litres. 
Construction of plugs. — (a) Sugared glass-wool. 
(b) Sugared glass-wool and sugar-powder. 
Rate. —5’3 strokes per minute. (Tube exposed 12 minutes.) 
~ 7 . . n , , . f 40 moulds. 
Colonies in flasks. — (a) 55 j ^ ^ 
(b) 3 moulds. 
No. 2. Flask method. 
Volume of air = 18 litres. 
Construction of 'plugs. — (a) Glass-wool only. 
(b) Sugared glass-wool and sugar-powder. 
Rate. —7*2 strokes per minute. (Tube exposed 10 minutes.) 
Colonies in flasks. — (a) 55 j ^ C10ll ^ s - 
f 2 moulds. 
5 {oli q . 
* This tube was much spoilt by liquefying colony; the number is, therefore probably too small. 
u 2 
