An EJJciy on bleaching. 107 



by one very ftriking character-: that of trees almoft always 

 contains tanning principle, or gallic acid; that of textile 

 plants never pofletfes any. The lap, therefore, is nothing 

 elfe than real vegetable chyle; a nutritive juice, compoied of 

 water, mucilage, and fugar, with fome portions of carbon, 

 phofphorus, and lime. 



Thefe preliminary observations are indifpenfably neceffary 

 for comprehending the theory of the operations to which 

 hemp and flax are fubjeCted. Deprive thefe plants of their 

 fap as foon as they are pulled, decompofe the extraclo-muci- 

 Jaginous matter, which occafions the aggregation of their 

 filaments, and you will have performed the firft operation, 

 which is called watering. The hemp 'or *flax, tied up in 

 bundles, is immcrfed in itagnant or fpring water, in which 

 the bundles are prcfled down by means of ftones. Well 

 water and brackifn water mult be carefully avoided, as well 

 as that which flows over gypieous foil. Such water accele- 

 rates putrefaction, and hurts the quality of the hemp and 

 flax. This is perfectly agreeable to the principles of che- 

 miltry; it is thus that a little fait accelerates animal putre- 

 faction, while a great deal tends to prevent it. The portion, 

 of faiine fub (lances taken up by the water hattehs corruption 

 by extending the putrid fei mentation, which ought to ope- 

 rate only on the juices, even \o the filaments, which it 

 blackens and fpoils. 



The fibres of flax are feppratcd by letting them remain 

 in ftagnant water until the mucilaginous membranes which 

 connect them are deftroyed by putrefaction. During its im- 

 merfion their fap is decomposed and diflhlved, the bark Se- 

 parates from the ligneous body, and the fibres are infulated. 

 Some days are fufficicnt for the procefs of watering. 



To afeertain the period of watering, which always varies 

 according to the kind of plants, the degree of their maturity, 

 and the nature of the lap, a handful of the flax is taken from 

 the pond, and broken and rubbed between the fingers: if 

 the flalks are ltill green, but brittle, and break with the lead 

 effort, the bundles mult be taken out : a longer. immerfion 

 might extend the decomposition even to the fibrous texture. 

 The putrefeence decompofes the water; there is formed car- 

 bonated hydrogen pettilcntially feetid ; the fi flies die, and the 

 air becomes infected. In countries where a great deal of 

 hemp and flax are cultivated, there are laws which forbid 

 thefe fubllances from being watered in rivers and other 

 Ji reams. 



The hemp and flax, when taken from the water, are fpread 

 put on the graft to dry. During the fermentation and de- 



compofition 



