Chemistry. — "Influence of (liferent compoumU on the destruction 

 of monosaccharids by sodiunihydroxide and on the inversion 

 of sucrose by hydrochloric acid. HI. Constitution-formula of 

 the hydroxybenzoic acids and of sulfanilic aci(C\ By Dr. 

 H. I. Waterman. (Couinmnicated by Prof. J. Böeseken). 



(Communicated in the meeting of September 29, 1917). 



Benzoic acid, salicylic acid and meta- and para-hydroxybenzoic acid. 

 In a previous communication M 1 have proved that in alkalic solution 

 phenol behaves as monobasic acid. It can be expected that in alkalic 

 solution benzoic acid will act as monobasic acid. This expectation 

 has been confirmed b}' the experiments. 



According to the said properties of phenol on the one hand, 

 benzoic acid on the other hand it might be supposed that in alkalic 

 solution the three hydroxybenzoic acids would behave as two-basic 

 acids. It has been proved that this is only the case with meta- and 

 para-hydroxy benzoic acid. Salicylic acid on the contrary in alkalic 

 solution acts as mono-basic acid. The results of the referential experi- 

 ments are united in table I" and P. 



From the polarisation at the beginning of the experiments is proved 

 that neither benzoic acid nor the three hydroxybenzoic acids have 

 considerable influence- upon the polarisation of glucose (table I" and 

 I''). Whilst the presence of 5 cm'' of 1,06 normal sodium-hydroxide- 

 soliition after Sg hours has lowered polarisation from -|- 11,1 to 

 respectively -|- 5,8 and +5,9 (N°. 5 and 8, I"), the addition of 1 milli- 

 gram-molecule of salicylic acid and benzoic acid has caused that the 

 polarisation has only been lowered to -f- 6,4 and -j- 6,6 (N". 6 and 7,1"). 



Analogous results were obtained with the same experiments after 

 ±6^ hours; under the influence of 5 cm" of 1,06 normal NaOH- 

 solution the polarisation has here been lowered to respectively -|- 3,3 

 (N». 5) and + 3,1 (N^ 8), at N". 6 and 7 only to + 3,9 and -f- 4,0. 



1 milligram molecule of the said acids compensates the action of 

 something less than 1 cm'' of 1,06 normal NaOH-solution ; salicylic- 

 acid and benzoic acid behave therefore as about monobasic acids. 

 If salicylic acid would act as two-basic acid, the polarisation of 

 N°. 6 (I") after 3| and 6^ hours should not be respectively -)- 6,4 



1) These Proceedings, April 27, 1917. Vol. XX p. 98. 



