248 CHEMICAL INFLUENCES ON YEAST. 



covery made by H. WILL (I.) and (at a later date) by C. WEHMER 

 (VII.), and confirmed by H. FLECK (I.) This is utilised in the 

 practice of preserving fruit (see vol. i. p. 108). Comparative tests 

 made by WEHMER (XV.) on Frohberg yeast with benzoic acid and 

 its three monoxy-derivatives, showed that 0,1 per cent, of the 

 first-named and also of its ortho-derivative (salicylic acid) entirely 

 prevent the development of yeast, though the m- and p-oxybenzoic 

 acids in the same concentration have no appreciable influence. 

 According to G. HEINZELMANN (VI.), o.i grm. of salicylic acid per 

 litre has a stimulating rather than an injurious action (see vol. i. 

 p. 104), whereas 0.37 per cent, is fatal to yeast; and similar results 

 were obtained by H. WILL (I.) The behaviour of yeast toward 

 cinnamic acid was reported on by FLECK (I.). Saccharin, which 

 was found by BURKARD and SEIFERT (I.) to have little effect 

 on yeast, is stated by MACHELEIDT (I.) to prevent fermentation in 

 hopped wort when used in the proportion of i per cent. No 

 appreciable influence in this connection could be detected by 

 G. BRYILANTS (I.) with 0.7 per cent, of phenolphthalein. The 

 behaviour of yeasts toward certain alkaloids was investigated by 

 CL. FERMI and E. POMPONI (I.). 



