576 
Richards . — The Respiration of 
Experiment 33 , 
60 grams of twigs of Salix alba in pieces about io cm. long. 
Had been gathered in the open, and kept in laboratory nine 
days before the determinations were made. Air-current, 3-5 
litres per hour. 
Date. 
Time. 
Tempera- 
ture. 
mg. C0 2 
produced 
per hour. 
i. 23. ’96 
8-55 - 9-55 a.m. 
20°-8 
II.40 
9 9 
9-55 ~ io -55 » 
20°.6 
I2-8o 
99 
10.55 ~ n-55 » 
20°-6 
12-10 
Twigs split longitudinally in several pieces. 
i. 23. ’96 
1.30 - 2.30 p.m. 
20°-4 
17'30 
2.30- 3.30 „ 
20°.8 
17-80 
99 
3.30- 4.30 ,, 
20°-4 
17-40 
>> 
4-30 - 5-30 „ 
20°-3 
I7-20 
5.30- 6.30 „ 
20°-2 
I7-20 
9 9 
6.30 - 8.00 „ 
20°. 3 
I7-60* 
i. 24. ’96 
II.07 “ 12.07 }> 
20°-6 
I7-00 
» 
12.07 “ 1-07 » 
2o°-5 
18-10 
99 
1.07 - 3.07 „ 
20°-4 
19.50* 
99 
3.07 - 5.07 „ 
20°-2 
16-80* 
i. 27. ’96 
9.15 - ii. 15 a.m. 
20°-2 
16-90* 
* Reduced to value of i hour. 
B. 
In the experiments made to determine the relation between 
the amount of C0 2 produced and of 0 2 absorbed, the time 
interval was always two hours. The apparatus used and the 
method of analysis of the air has already been described \ For 
the purpose of these experiments the air of the laboratory 
was perfectly pure, containing but a bare trace of C0 2 . The 
amount of 0 2 in the air is taken in the following tables at 
1 See this paper, page 534etseq. 
