_364 True and Hunkel, The Poisonous Effect Exerted etc. 



four hours to be little affected, nearly all respondiug to a plas- 

 molysing Solution promptly and in the normal manner. Fila- 

 ments of the same alga placed in a Solution of para-cresol con- 

 taining 1/200 gram-molecule per liter were found after twenty- 

 four hours to be dead, no surviving cell being seen. The pro- 

 toplast had shrunken away from the wall, the Chlorophyll band 

 had broken up, and aggregated into several masses, and the pro- 

 toplasm contained large numbers of highly refractive granules. 

 In a Solution containing 1/400 gram-molecule per liter, the Chloro- 

 phyll band seemed somewhat disturbed, but the cells were not 

 seriously injured and appeared to recover; those placed in a 

 Solution of half this concentration seemed to be unaffected. 



Experiment seems to indicate that the toxic action of the 



cresols is chieflv due to the undissociated molecules in the 



+ 

 Ortho and meta Compounds, the effect in part being due to H ions 

 and perhaps also in some degree to the anions. 



From these results, it appears that the displacement of one 

 of the hydroxyl groups of a di-atomic phenol by a methyl group 

 may result in a Compound of greater toxicity, and this toxic action 

 will depend for its intensity somewhat on the position which this 

 radicle occupies in the molecule, the strongest action here character- 

 izing the para Compound. 



By introducing an isopropyl group (— CH[CH3]2) into the 

 para position to the methyl group in ortho- and meta-cresols, 

 we obtain carvacrol and thymol respectiv^elv w'ith the formulae : 

 carvacrol, Ce Hs (CHs) (OH) (Cs H7) = "'l : 2 : 4, and thymol, 

 CeHs (CHs) (OH) (C3H7) = 1:3:4. Since no study of the 

 electrical conductivity of these Compounds has been made as far 

 as the writers are aware, evidence of this nature could not be 

 here cited. 



Carv?crol, CeHs (CHs) (OH) (C3H7) = 1:2:4. 



Table XXV. 

 Begun Feb. 27, 4 : 30 P. M. 



8. Leneth Mch. 2. 



Conditio II. 



Dead. 



AUve. 



