THE MICRO-ORGANISMS PRESENT IN THE ATMOSPHERE. 117 
Y. Roof of Science Schools, South Kensington Museum. June 25th, 1886. 
12 litres of air yielded. 114 colonies. 
Control-tube. 34 ,, 
Wind moderately strong. 
VI. Ditto. June 28th, 1886. 
12 litres of air yielded. 49 colonies. 
Control-tube. 29 
Wind moderate, but variable. 
VII. Ditto. Same day. 
11 litres of air yielded. 52 colonies. 
Control-tube. 15 
Wind moderate, but not quite so variable as in previous experiment ; 
increased very much in strength at close of experiment. 
VIII. Ditto. June 29th, 1886. 
12 litres of air yielded. 45 colonies. 
Control-tube. 11 ,, 
Wind very gentle and fairly constant. 
IX. Ditto. June 30th, 1886. 
10 litres of air yielded. 75 colonies. 
Control-tube. 15 „ 
(approximately) 
(Owing to strength of wind, the open extremities of the tubes were 
directed quite away from the wind.) 
Wind very considerable in strength. 
X. Ditto. July 2nd, 1886. 
12 litres of air yielded. 51 colonies. 
Control-tube. W » 
Wind gentle throughout the greater part of experiment. 
XI. Ditto. July 6th, 1886. 
12 litres of air yielded . . 
Control-tube. 
Wind very considerable. 
XII. Ditto. July 9th, 1886. 
12 litres of air yielded. 59 colonies. 
Control-tube. ^ » 
Wind strong. 
78 colonies. 
48 
