Tru« aud HuaUel, The Poisouous Effect Exerted etc. 293 



Table I. 

 Begun March 22, 3 : 20 P. M. 



As appears in Table 1., phenol ranks among the substanees 

 strongly harmful toward the lif'e of the lupines, the iirst concen- 

 tration in which these plants could survive beiug one gram-mole- 

 cule in 400 liters. Experiments') carried out with Spirogyra 

 indicated that the alga tolerates this poison in larger quantities 

 than the lupine. Small tufts of filaments were rinsed out in a 

 Solution of the strength to be used in the experiment to avoid a 

 dilution of the same and placed in the desired concentration. After 

 about twenty-four hours, their condition was examined and plas- 

 molysis with a 5 per cent saltpeter Solution was regarded as 

 sufficient evidence of life in the cells. The limit-concentration for 

 Spirogyra was found to be one gram-molecule in 200 liters. 

 In this concentration, Bokorny-) found that this alga formed 

 starch in five days. In a 0,1 per cent Solution, Loew**) obser- 



') True, R. H. Algae und antiseptics. (Phanii. Kev. X\'. ].. 15-2. 1897.) 

 ^) Bokorny, Cheni. Zeitung. 1894. No. -1. Cit. Biolog. Contralbl. 

 :XVII. p. 7. 1897. 



') Loew, Natürliches System der Giftwirkuugen. p. 50. 



