USE OF BACTERIA IN THE ARTS. 45 



obtained from the husk of the cocoanut by the 

 same means. The unripened husk is allowed to 

 steep and ferment in water for a long time, six 

 months or a year being required. By this time 

 the husk has become so softened that it can be 

 beaten until the fibres separate and can be re- 

 moved. They are subsequently made into a num- 

 ber of coarse articles, especially valuable for their 

 toughness. Door mats, brushes, ships' fenders, 

 etc., are illustrations of the sort of articles made 

 from them. 



In each of these processes the fermentation 

 must have a tendency to soften the desired fibres 

 as well as the connecting substance. Putrefac- 

 tion attacks all kinds of vegetable tissue, and if 

 this "retting" continues too long the desired 

 fibre is decidedly injured by the softening effect 

 of the fermentation. It is quite probable that, 

 even as commonly carried on, the fermentation 

 has some slight injurious effect upon the fibre, 

 and that if some purely mechanical means could 

 be devised for separating the fibre from the wood 

 it would produce a better material. But such 

 mechanical means has not been devised, and at 

 present a putrefactive fermentation appears to 

 be the only practical method of separating the 

 fibres. 



Sponges. A somewhat similar use is made 

 of bacteria in the commercial preparation of 

 sponges. The sponge of commerce is simply 

 the fibrous skeleton of a marine animal. When 

 it is alive this skeleton is completely filled with 

 the softer parts of the animal, and to fit the 

 sponge for use this softer organic material must 

 be got rid of. It is easily accomplished by rot- 

 ting. The fresh sponges are allowed to stand in 

 4 



