﻿1903] 



CHEMICAL STIMULATION 



171 



ments with boiled water must have been that the precipitated 

 carbonate was gotten rid of by changing bottles. 



NiClg was tested similarly to AgNO^. 



The acceleration 



during the first 



two 



TABLE XXVIL 



May 13. Test of NiClg, The experiment bottle 

 hours is decidedly more contains Elodea in 400^^*^ " Neptune '' (a triple- 



Considerable with the distilled commercial water). The control bottle 



-„ ^ , . , , contains 400'^'= tap water. 



tap water than with the 

 Elodea- The rather 

 rapid decrease, while " 



Time 



Experiment 



the Elodea 



is practi- 



11:05-12:55 

 12:59 

 12:59- 2:59 



2:59- 6: 23 



M 



1000 



0.027 

 NiCL in both 



Control 



0.003 



0.03s 

 0.034 



bottles. 



0.026 

 0.018 



point that way, as it might 



cally constant, might 



indicate that the effect 



on the latter is on the 



proteid, but does not necessarily 



merely be because the salts in the sap are not acted on at once. 



I deemed it not worth while to test the action of some other 

 poisons on Elodea, since, as table XXVIII shows, they all drive 

 COg from tap water. 



I have been assuming that the cell sap contains salts like 

 those in the tap water, from which CO^ can be driven by the 



TABLE xxviii poisons applied. This cannot well 



May 2 and 3. The subject of each of ^^ doubted; Still it seemed de- 



these tests was 400^^ tap water. sirable to prove it, if possible, by 



direct experiment. For this pur- 

 pose I crushed a mass of Elodea 

 from which I should say the CO3 

 evolved at the temperature of the 

 experiment could not possibly 

 have been in excess of 0.060*^'' N 

 CI in bottle. per hour. The sap was squeezed 



out and the material washed and 



Of course the 

 plants were most thoroughly 

 washed with distilled water be- 

 fore crushing. The sap was then 

 diluted to 150 ^^ and placed in 

 the ''control" bottle, while the 



Ti 



me 



Experiment 



2:36- 6:06 

 6:06 



6:06- 7:21 

 8:10- 9: 16 



9-'i6 



100 



Co 



9' 16-10: 22 



10: 18-12:52 



12:52 ^ 



loo 

 12:52- 2:20 



6:40- 8: 20 



0:20 • 



1000 



8:20- 9:26 



N 

 loo 



0.003 



CI 2 in bottle, 

 0.144 



0.000 



H 



Pb(N 



1.677 



o.ojy 



Oa)^ inbottle. 



0.776 

 0.003 



rCd(NO' ). inbottle. 



squeezed again. 



^•^^'^ 



