J 48 
DR. P. F. FRANKLAND ON THE QUANTITATIVE ESTIMATION OF 
Control-tube, containing plug- of sugared glass-wool, exposed 41 minutes : — 
Colonies in flask, 0. 
7 . r . 77 , 7 „ . fNo. 1 (sugar-wool), 32 colonies. 
10 litres of air yielded, therefore, in\ __ . 7 
J J J [No. 2 (glass-wool), 33 
No. 3. Hesse’s method. 
Volume of air =10 litres. 
Colonies in tube . . .32 
,, control-tube 2 
14 moulds, 
liq. 
1 mould. 
0 liq. 
X. Roof of Science Schools. October 29, 1886. Wind S.W., gentle, with occasional 
gusts; fairly constant in direction. Roads and pavement wet. Roof still damp 
from previous rain. 16 0, 3 C. 10.51 a.m. to 11.38 a.m. 
No. 1. Flash method.— (Double plugs.) 
No. 2. ,, (Lost.) 
No. 3. Hesse’s method. 
Nos. 1 and 2 were alternated in aspiration; No. 3 was simultaneously 
aspirated in close proximity, the tubes being inclined at the same angle. 
No. 1. Flash method. 
Volume of air =18 litres. 
Construction of plugs. —(a) Glass-wool only. 
( b ) Sugared glass-wool and sugar-powder. 
Rede. —3’6 strokes per minute. (Tube exposed 17 minutes.) 
~ 7 . . f 27 moulds. 
Colonies m fiashs. — (a) 30 j ^ ^ 
(b) o. 1C1 ' 
Control-tube, containing plug of sugared glass-wool, exposed 49 minutes :— 
Colonies in flask, 1 j° “° ulds - 
lo liq. 
12 litres of air yielded, therefore, in No. 1, 20 colonies. 
No. 3. Hesse’s method. 
Volume of air = 12 litres. 
~ 7 . . 7 f 12 moulds. 
Colonies m tube . . . 35f .. 
I 1 hq. 
7 7 f 3 moulds. 
,, control-tube . 61 
1 0 liq. 
These experiments clearly demonstrate that the results obtained by the flask 
method and by Hesse’s method are in remarkable concord when the experiments are 
