TRANSACTIONS OF SECTION K. 845 



these advances in tlie manufacture of pure butter with constant flavour, the days 

 of ' diseased ' butters seem numbered. 



Properly considered, the manufacture of cheese is a form of microscopic garden- 

 ing even more complex and more horticultural in nature than the brewing of beer. 

 From the outset, when the cheesemaker guards and cools his milk till his stock is 

 ready, he is doing all he knows how to do to keep down the growth of the germs 

 introduced into the milk ; he then coagulates it, usually with rennet — an enzyme 

 of animals, but also common in plants — and the curd thus prepared is simply 

 treated as a medium on which he grows certain fungi and bacteria, with the need- 

 ful precautions for favouring their development, protecting them against the in- 

 roads of animal and plant pests, and against unsuitable temperature, moisture, 

 access of light, and so on. Having succeeded in growing the right plants on his 

 curd, his art then demands that he shall stop their growth at the critical period, 

 and his cheese is ready for market. 



The investigations of Duclaux, Wiegmann, and others on the Continent, of 

 Conn in America, and of Lloyd in England, to say nothing of other workers now 

 busy at this subject in various parts of the world, are getting at the particular 

 forms of fungi concerned in so altering the constitution of curd that it becomes the 

 very different article of food we call cheese, and they have even determined to 

 some extent what role is played by these plants in giving the peculiar odours and 

 flavours to such different cheeses as Camembert, Stilton, and Eoquefort. It is 

 known, for instance, that a certain fungus {Pemcilliwn) cultivated on bread is 

 purposely added to Roquefort, and that it destroys the lactic and other acids and 

 so enables certain bacteria in the cheese, hitherto inhibited in their actions by 

 these acids, to set to work and further change the medium, whereas in making 

 Emmenthaler cheese the object is to prevent this fungus thus paving the wav for 

 these bacteria. Pammel claims to have discovered a bacillus which gives a peculiar 

 and much-admired clover aroma to certain cheeses, and according to recent state- 

 ments a definite Streptococcus is responsible for the peculiarities of certain Dutch 

 cheeses, and so on. Nevertheless, we are still profoundly ignorant of most of the 

 forms concerned in the ripening of cheese, and every research which throws light 

 on this difficult and complex subject, and so paves the way to rendering uniform 

 and certain this at present most haphazard and risky manufacture will be doing 

 service to the State. Considering that Cohn only discovered that the ripening 

 process is due to bacteria in 1875, and that Duclaux only published his researches 

 on Tyrothrix in 1878, we can scarcely be surprised that the interval has not been 

 long enough for the isolation and study of the numerous and curious forms, several 

 hundreds of which are now imperfectly known. Nevertheless, there are sio-ns of 

 advance in various directions, and researches into the mysteries of Roquefort, 

 Gorgonzola, Emmenthaler, and other cheeses are being industriously pursued on 

 the Continent. Even as I write this comes the news that Freudenreich has dis- 

 covered the coccus which causes the ripening of Emmenthaler cheese. It is not 

 impossible that the much more definite results obtained by investigations into the 

 manufacture of the vegetable cheeses of China and Japan will aid bacteriologists in 

 their extremely complex task. 



These vegetable cheeses are made by exposmg the beans of the leguminous 

 plant Glycine — termed soja-beans — to bacterial fermentations in warm cellars, 

 either after preliminary decomposition by certain mould-fungi, or without this. The 

 processes vary considerably, and several difl"erent kinds of bean-cheeses are made, 

 and known by special names. They all depend on the peculiar decompositions of 

 the tissues of the cotyledons of the soja-bean, which contain 35 to 40 per cent, of 

 proteids and large quantities of fats. The softened beans are first rendered 

 mouldy, and the interpenetrating hyphse render the contents accessible to certain 

 bacteria, which peptonise and otherwise alter them. 



Here, however, I must bring this subject to a close, and time will not permit 

 of more than the mere mention of the vinegar fermentation, to which Mr. Adrian 

 Brown has lately contributed valuable knowledge, of the preparation of soy, a 

 brine extract of mouldy and fermented soja-beans, of bread-making, and other 

 equally interesting cases. 



