CHEESE-MAKEKS' RECIPES. 325 



and which proved capable of causing puffiness in cheese. This 

 microbe is shown in Plate I. Fig. i. 



The second method is founded on a different basis. Whereas 

 Freudenreich devoted his attention to the discovery of specific 

 inflation ferments, FR. BAUMANN (I.), on the other hand, en- 

 deavoured to ascertain the external conditions under which a 

 microbe producing the normal pitting of cheese would become 

 the cause of inflation. An example of this is afforded by the 

 Bacillus diatrypeticus casei, discovered by him. This organism, 

 when sparsely inoculated in curd prepared from Pasteurised milk, 

 produces a "blind" cheese, i.e. one containing merely a few holes; 

 but when it is added in large amount, it gives rise to puffiness. This 

 facultatively anaerobic fission fungus is a non-motile capsule bacil- 

 lus, generally 1.5 p in length and 0.7 //. in breadth ; a photographic 

 representation is given in Plate I. Fig. 2. In media containing 

 sugar it liberates a gas chiefly consisting of carbon dioxide along 

 with a not inconsiderable portion of hydrogen ; and in addition to 

 these products alcohol and lactic acid are formed. 



If this bacillus be inoculated into a fresh curd prepared from 

 non-Pasteurised milk, and consequently rich in a variety of bac- 

 teria, a struggle ensues between them. In presence of a superior 

 force of species that do not generate gas, the B. diatrypeticus casei 

 is suppressed, and " blind " cheese will result. On the other hand, 

 when the restrictive power of the other organisms is merely 

 sufficient to moderate, but not prevent, the development .(and 

 consequently gas-producing power) of our bacillus, then the pitting 

 will be normal ; whilst, if finally these adverse influences be almost 

 entirely lacking, " puffy " cheese results. No rejection of this ex- 

 planation is implied by the mention of the error into which its 

 author has fallen in attributing to his bacillus alone the capacity 

 of producing pitting the inaccuracy of which assumption has 

 been noted, inter alia, by ADAMETZ (VIII.). 



182. Cheese-makers' Recipes. 



In the light of Baumann's discovery, the reason for a number 

 of (apparently pedantic) rules current among cheese-makers both 

 for the production and subsequent treatment of the curd is made 

 clear. The careful adherence to certain temperatures during and 

 after setting; the time of exposure to their influence; the nature 

 of the mechanical treatment, and even the extent of the pressure 

 applied to the moulded curd in the press, all these conduce to the 

 result the cause of which is certainly unknown to the operators 

 that a certain bacterial species attains pre-eminence. 



The researches published by FR. SCHAFFER (III.) and FREUD- 

 ENREICH (VIIL) in 1895 tend to elucidate the processes occurring 

 during the after-warming of the curd. As has already been in- 

 dicated, the freshly precipitated curd is kept for a short time at a 



