268 AGRICULTURAL BACTERIOLOGY. 



phenomenon occurring in cheese which has frequently been of 

 serious import. Cases of cheese-poisoning are frequently 

 reported which, upon investigation, prove to be only too 

 well founded. The poisoning in these cases is due to the de- 

 velopment of a violent poison in the cheese, known as tyro- 

 toxicon. This poison does not make itself evident in the taste, 

 but acts very violently upon the person eating the cheese. 

 The poison is produced by a species of bacterium which grows 

 in the cheese during the ripening. Against such a source of 

 trouble our present knowledge of the sources of bacteria gives 

 us no means of guarding, beyond the general suggestion of 

 strict cleanliness in all matters connected with the dairy or 

 cheese factory. 



PRACTICAL APPLICATIONS. 



Of course attempts have been made to apply these bacteri- 

 ological discoveries to the practical manufacture of cheese. 

 Insurmountable difficulties have hitherto stood in the way of 

 any very great success in this line. The only really practical 

 application of cultures to cheese-making upon any extensive 

 scale is found in Holland in the manufacture of the Edam cheese. 

 The Edam cheese is a hard cheese made in a very simple 

 manner ; but the Hollander has learned that he can use an 

 artificial culture in its manufacture to considerable advantage. 

 The culture which he uses is known as slimy whey and is pre- 

 pared by adding to the milk some whey which has shown 

 a slimy fermentation. How the process started is not known. 

 It certainly did not start with the bacteriologist, but was a 

 simple empirical discovery. The culture is carried from farm 

 to farm and is grown by the cheese-maker without his under- 

 standing its nature. When analyzed, the slimy whey is found 

 to be a mixture of organisms, the most prominent of which is 

 a slime-producing coccus which gives the characteristic slimi- 

 ness. When this slimy whey is added to the milk, and the milk 



