82 A DISEASE GARDEN 
Fermentative Industries. 
Vinegar Indigo 
Lactic Acid Butyric acid 
Tobacco curing Opium (smoking) curing 
Dairy Industry. 
Cream ripening Cheese ripening 
Agriculture. 
Nitrification Sprouting of seeds 
The Silo Fertility of the soil 
Food Products. 
Game flavour Sauer Kraut. 
Purification of Sewage. 
The effects of friendly bacteria are seen in the manu- 
facture of linen, hemp and jute ; in the preparation of indigo ; 
the curing of opium and the production of vinegar. 
The fragrance and aroma of tobacco are due to bacterial 
causes. re the tobacco leaves are fit for use, they have to go 
through many processes, some of which, at least. are ferm 
entative. “ 'The special quality of tobacco is in part dependent 
upon the pecuhar type of fermentation that gives rise to the 
flavour and aroma of the tobacco, and as the number of 
species of bacteria which are found on the tobacco leaves, 
in the various stages of its preparation, is quite large, it is 
inevitable that the different kinds of bacteria will produce 
different results as to flavour and grade in the fermenting pro- 
cess.” 
The dairyman has to put up occasionally with the enmity 
of unfriendly bacteria ; the souring of his milk ; its somewhat 
bitter, tainted or soapy taste ; its blue, red, or yellow colour ; 
its slimy consistence are due to the growth in the milk of un- 
usual bacteria. On the other hand, the ripening of his cream 
and the ripening of his cheese, giving it the special flavour, 
which finds acceptance in the market, are but the effects of 
his allies the friendly bacteria. The flavour of cheese is due 
to a bacterial growth of a fermentative character, giving rise to 
decomposition, which, in the case of Limburger and others, 
is not very difficult to discover. 
To the agriculturalist the friendly bacteria are as essential 
as the soil or the seasons. It has been asserted, I don’t know 
