﻿132 



BACON. 



October 23, a. in. The tubes were now placed in the laboratory in diffused 

 light; the next morning at 7.50 the reading was — 



At S a. 



(a) 



(6) 





35.0 



6.0 





again placed in 



the sunli 



ght. 



Time. 



(a) 



(&) 



8.00 to 8.20 



18 



3 



8.20 to 8.30 



35 



12 



8.30 to 8.38 



12 



17 



8.38 to 8.45 



25 



40 



8.48 to 8.5C 



10 



31 



8.59 to 9.14 



25 



40 



9.16 to 9.30 



26 



36 



9.32 to 9.44 



22 



38 



9.46 to 9.56 



22 



38 



9.59 to 10.12 



22 



37 



10.14 to 10.25 



22 



36 



10.27 to 10.43 



22 



36 



10.45 to 10.59 



25 



38 



11.01 to 11.12 



24 



38 



11.42 to 11.58 



25 



40 



October 23, p. m. The tubes stood in the diffused light of the laboratory 

 from 12.00 to 1.00. 



(a) (b) 



8.5 24.5 



Therefore (a) in two hundred and forty-five minutes gave 297 cubic centimeters 

 of gas, as compared with 561 cubic centimeters obtained from (b). The solution 

 containing the pitchblende had the greater initial velocity which may possibly be 

 due to the presence of iron salts, because the latter at first markedly catalyze solu- 

 tions of oxalic acid, as is shown by later experiments given below, but radio- 

 activity would seem to have little or no influence on the rate of the reaction, a 

 conclusion which is confirmed by other experiments of the same character; the 

 solution derived from pitchblende always exhibiting a slower rate than the ones 

 containing uranium salts. 



Experiment 10. — October 24, p. m. 



(a) 1 gram ferric chloride (sublimed). 

 5 grams oxalic acid. 

 100 cubic centimeters water. 

 (6) 5 grams oxalic acid. 



100 cubic centimeters water. 



Picric acid added sufficient to give a color as nearly as 

 possible like that of the uranium acetate solution used 

 in (b), experiment 9. 



Time. («) (&) 



1.25 to 2.15 40 0.5 



2.26 to 3.20 40 0.5 



The next morning the two tubes were place in sunlight at 8.00 a. m. 



At noon 



(a) 

 2 



(b) 

 0.7 



