True aud Hunkel, The Poisonous EfiFect Exerted etc. 327 



Phloroglucin. CeHs (OH) (OH) (OH) =1:3:5. " 



Table XV. 

 Begim May 1, 2:30 P. M. 

 Gram-mol. per 

 liter. 



1/200 



1/400 



Phloroglucin is much more stable than the preceding Com- 

 pound and is muchless poisonous. The toxic action is probably 

 due to the undissociated Compound. 



Although, as we have seen in a number of cases, certain com- 

 plications have prevented us from obtaining the toxic value for 

 all of the above enumerated substances, some changing their 

 nature so soon after the preparation that our results are question- 

 ably due to the substances named, in cases, still we may be 

 permitted to draw some conclusions regarding the eflfect exerted 

 by replacing hydrogens of the benzol ring by OH groups. 

 Omitting the results obtained for pyrocatechol, hydroquinone and 

 pyrogallol, these being manifestly not the effects produced by 

 the unaltered Compounds, we lind remaining as stable substances 

 one each of the mono-, di-and tri-atomic phenols, benzophenol, 

 Ce HöOH, with a toxic value of 1/400; resorcinol, CcHs (OH) (OH) 

 1:3, with a toxic value of 1/200, and phloroglucin, Ce Hs (HO) 

 (HO) (HO), ] : 3 : 5, with a toxic value of 1/400. From these 

 examples, it thus appears that the increase in the number of OH 

 groups replacing H in the benzol ring exerts no piain efFect on 

 the toxic action, neither a regulär increase nor a regulär de- 

 crease being found. 



Loew') reports that with the replacement of the H atoms of 

 the benzol ring, the poisonous activity increases in dircct propor- 

 tion to the number of hydrogens replaced by OH groups. 



A number of phenylic Compounds, derivatives in tiic main, 

 obtained by introducing various radicles into the loregoing phenols 

 or their homologues were tested in the hope that we might be 

 able to ascertain somcwhat concerning the relation of molecular 

 structure to physiological action for the plants under study. 



By replacing one of the OH groups of a di-atomic phenol 

 with a methyl group CHs, we obtain the three isomeric cresol 

 Compounds. These substances were tested with reference to their 

 action on the lupines. (To be continued.) 



') Loew. Ueber Giftwirkung. (Archiv für diu gesammte Physiologie. 

 XL. 1887. p. 440. — Cited in Davenport'a Experimental Morphology. New 

 York 1897. p. 18 ) 



