﻿1903] 



CHEMICAL STIMULATION 



167 



Both bottles were treated in the same way another hour, with practically the same 

 result. After the first hour most cells were alive in both bottles; but after two hours 

 the plants of exp. B were practically dead. 



The result of this experiment made it appear exceedingly 

 probable that CO^ was evolved after death under the influence 

 of copper. The next two experiments show that this is the case. 



TABLE XIX. 



December 26. Test of 



M 



CUSO4. 



TABLE XX. 



2000 

 Plants boiled for twenty minutes in 



distilled water; then cooled and 



washed until no COg came off. 



January 9. Test of 



M 



1167 



CuS04. 



This material was boiled twice in 

 double-distilled water. 



Time 



Experiment 



Time 



3:39-4:51 



4:51 



4:51 

 5:57- 

 4:51- 



M 



CUSO4 



0.000 



2000 



■5:57 

 7:39 



7: 39 (total COg) 



in bottle, 

 0.082 



0.02Q 



0.140 



5:27-6:27 



6:27 



6:27-7:33 



Experiment 



M 



1 1 67 



CUSO4 



0.007 

 in exp. bottle 

 0.429 



This raised the question as to whether or not Zn might act 



in the same way on boiled Elodea. Experiment shows that it 

 does. 



Th 



ese results were con- 



TABLE XXI, 



strued as proving that dead 

 ** protoplasm" could be caused 

 to evolve CO^ by the action of 

 Cu and Zn. As a matter of 

 curiosity I made a similar ex- 



December 28. Test of 



M 



ZnSO^. The 



material was 

 washed until 



100 

 boiled under suction, and 



no CO3 came off. 



Time 



M 



E-vperiment 



000 



CuSO^ on 



permient, using - 



peptone (in distilled water) ; no 



CO2, or at most a trace, was 

 evolved. 



8 : 53-9 : 53 

 10 :04 



M 

 100 



ZnS04 



10 : 04-1 1 :04 



11 : 04-12 :22 (12.3 hrs.) 

 Total COo evolved 



0.000 

 in bottle. 



Q,02Q 



0.004 

 0.070 



The results of the experiments with copper on live plants are 

 summarized here, in the form explained in connection with the 

 similar table on 



zmc : 



■ - k i-LIx 



