True aud Huakel, The Poisonous Effect Exerted etc. 395 



Table XLII. 



Methyl salieylate. 

 Begun May 22, 4 : 25 P. M. 

 Gram-mol. per litcr. 



1/800 

 1/1600 



By replacing tlie acid hydrogen of salicylic acid with some 

 harmless ion, we are able to obtain some idea of tlie intcnsity ot 

 the action of thc anion, assuming relatively eomplete dissociation. 

 The Na Compound and methyl salieylate were studied in this con- 

 nection and gave, as Tables XL and XLI show, quite different 

 results. The low toxic valae of the sodium salt would bo expec- 

 ted, the hydrogcn ions, found to eonstituto in general the markedly 

 toxic agent in acids, being disposed of, practically harmless sodium 

 appearing instead. The remaining toxic activity, a still appre-^ 

 ciable quantity, is due to anions or to a possible residue of 

 undissociated molccules or to both. 



Methyl salieylate conducts itself somewhat diftercntly. Its 

 boundary-concentration is a much more strongly diluted Solution 

 than that of sodium salieylate. This greater toxicity is hardly to 

 be attributed to the presence of the methyl group (CHs). Pro- 

 bably hydrolytic dissociation takes place, forming methyl alcohol 

 and salicylic acid. As is shown by the persistence of the charac- 

 teristic odor, this hydrolytic Splitting up is only partial. It would 

 be expected that the salicylic acid thus split off would undergo 



4- 



electrolytic dissociation and a greater or less quantity of II ions 

 would appear in thc Solution, increasing proportionally its toxic 



+ 

 action. It is prol)ably, therefore, H ions which rendcr tlie So- 

 lution ot methyl salieylate so much more deadly than sodium sali- 

 eylate. 



In a recent work, Davenport^) states that .,by rcplaring 

 one of the H atoms of phenol by COOK (or carboxyl), thus pro- 

 ducing salicylic acid, the poisonous qualities are reduced". For 

 the lupincs and Si)irogyra, this statement seems not to hold, 

 as the following comparison of limit-concentrations shows. For 

 lupines this limit is 1/6400 gram-moleculc jx-r liter of salicylic 

 acid and 1/400 gram-molecule jter liter «>( i)henol; for Sjiiro- 

 gyra the limit concentration for salicylic acid is about 1.'2000 



•) Davenport, C. B., Expoiimontal Morpliology. Vol. I. is'.»; 

 p. 19. 



