﻿21 2;« 



These results ol' the respir:! lory process coiupared with those noted by the 

 above inenlioned students on the same subjecl show several apparent diverj^encies: 

 Elfving, who also experimented with seedlings of Pisum, noted that the CO^-pro- 

 duction is accelerated when the objects are exposed to a dose of ether until 15 per 

 cent by measure (Ki to 23 hours of exposure). Using this dose I found a consi- 

 derable retardation of the respiration, the dose corresponding to 07 c. c. ether per 

 liter air. This divergency may however be explained by the difference of the ex- 

 perimental arrangements. H^lfving placed the seedlings (50 plants) in an eudiometre 

 with a capacitj' of 170 c. c; 15 per cent by measure of vapour of ether in 170 c. c. 

 air represent 012 c. c. ether, an exceedingly small dose, but the largest used by 

 Elfving, and which to all likelihood represents the smallest ones I have used, as 

 it must be remembered that the plants absorb easily large quantities of ether 

 [Lauren p. 40]. Elfving never used doses, larger than the above mentioned one, 

 nor longer periods of exposure and so he had no chance of demonstrating a retar- 

 dation of the respiration produced by ether. 



As regards Lauren's results it must be remembered that the duration of the 

 exposure he used was always very short, the objects being exposed to ether only 

 one hour at a time. With regard to Pisum he observed however a considerable 

 acceleration of the respiration by 30 per cent by measure of ether; when greater 

 doses were used, the respiration was retarded and the plants were injured or died. 



A comparison based on numbers between his results and mine is impossible 

 on account of the above mentioned difference to which must be added that my 

 objects were exposed to ether in a closed jar, while the plants Lauren used for 

 his experiments were exposed to a current of air containing vapours of ether, a 

 circumstance which considerably influences the amount of ether absorbed by the 

 plants. Yet the same results may be arrived at, for both sets of experiments de- 

 monstrate an increase of the CO;, -production by small doses and a retardation by 

 large doses. 



As Claude Bernard did not observe in germinating corn any influence on the 

 respiratory process by the etherization, it must be owing to the circumstance that 

 he, as may be inferred from his report, did not at all perform quantitative ana- 

 lyses of the CO.j-production, only demonstrating (jualitatively the CO^-production. 



Experiments on the Effect of Ether on the Nitrogenous Compounds of 



Seedhngs of Pisum. 



The seedlings used for the experiments on the respiration (except those used 

 in 1 and II) were crushed with alcohol and analyzed as for nitrogenous substances and 

 sugars in the above mentioned manner. The numbers of the experiments here and 

 in the results of the sugar-analyses refer to the numbers of the analyses of the 

 respiratory process. "Amides" states here the compounds which are not precipi- 

 tated by tannic acid : 



