SARCINA. . 159 



by the use of the usual liquids and gelatines. Certain materials, 

 for example, horse urine and dung, appear to be particularly 

 rich in pronounced Sarcina species. Their presence can easily 

 be verified also in malt and malt dust. It has not proved 

 possible as yet to determine the natural haunts for the beer 

 Sarcince. One reason for this is that such species cannot be 

 distinguished from others that do not attack the liquor, in an 

 ordinary micro-biological analysis. The only accepted con- 

 clusions are that all true beer Sarcince that have been exactly 

 investigated cannot thrive in alkaline substrata (ammoniacal 

 liquids or gelatine) ; that they form whitish masses in streak 

 cultures, and on the surface of stab-cultures ; that they 

 belong to the facultative anaerobes ; and further, that specially 

 favourable conditions for their development are to be found 

 in badly saccharified wort, and to some extent, according to 

 Miskowsky (as in the case of many other bacteria), in malt 

 extract with a high content of dissolved albuminoids (especially 

 albumoses and peptones) ; in such a liquid they may remain 

 for a long time unaltered ; and, lastly, that, like many other 

 bacteria, they appear to be checked by a large amount of 

 hop constituents. 



It follows that it is impossible to distinguish by any general 

 test whether Sarcina-\ike bacteria in yeast or beer are able to 

 produce a disease in beer. To answer this question we must 

 proceed experimentally a difficult investigation taking up 

 much time. It would, however, be obviously foolish to 

 neglect the usual test for Sarcina-like bacteria in yeast and 

 beer, for if they are observed there is always a possibility that 

 dangerous species may be present. It appears to be thoroughly 

 established by experience that, in the early stages of ferment- 

 ation, a weak growth of such bacteria may be concealed, and 

 at present the problem is to provide means whereby the 

 analyst may be able to detect minute quantities of these 

 organisms. Amongst such means may be adduced Claussen's 

 method for the treatment of yeast with minute quantities of 

 acid ammonium fluoride which checks the yeast cells, so that 

 a subsequent infection in wort-gelatine mainly gives a growth 

 of Sarcina colonies. The liquid prepared by Bettges and 

 Heller may also be used ; it consists of sweet wort completely 



