418 



HISTORY OF THK VEGETABLE KINGDOM. 



part of tlie hemp, it certainly is advisable to lay 

 the hemp in water as soon as can be after it is 

 pulled, because the more tliere is of the natural 

 moisture left in this glutinous substance tlie 

 sooner the putrefaction would begin. If either 

 by design or by accident the hemp has been 

 dried, the putrefaction comes on more slowly 

 and uncquablj', and the fibres contract a hard- 

 ness which the steeping will not afterwards easily 

 correct." 



Marcandier is of the same opinion as the 

 writer just quoted, and farther adds, that hemp 

 newly gathered requires only four days' immer- 

 sion in water, but if it has been previously dried, 

 eight or ten days will scarcely suffice to produce 

 a similar effect, and if the water be hard or of a 

 very cold temperature, a fortnight or three weeks 

 may be found necessary. 



Mere exposure to the air is sometimes substi- 

 tuted for the water steeping; this is called dew- 

 retting. The hemp to be so treated is stacked 

 and covered during the first part of the winter, 

 and in January and February is spread upon 

 meadow land and whitened with the frost and 

 snow. The fibres of the plants thus treated are, 

 however, always much inferior to those which 

 are retted by water, and they are fit only for the 

 coarser yarns. 



In the cold regions of some part of Russia 

 and Sweden the snow which falls so abundantly 

 is made the means of separating the fibres from 

 the useless part of the plant. The hemp pre- 

 viously dried instead of being steeped in water, 

 is, after the first foil of snow, spread on the 

 ground to receive a fresh accession of snow upon 

 its surface; and this, when dissolved in the spring, 

 leaves the hemp in such a state that the fibres 

 are readily disengaged. In some parts of Livonia 

 a more complicated method is pursued, which it 

 is said enhances the value of the hemp twenty- 

 five or thirty per cent. 



A spot where there is a fall of clear water is 

 selected, and five or six basins of about two feet 

 deep are made, one beneath the other; they are 

 divided by slight banks of clay, and communi- 

 cate with each other by means of a small aper- 

 ture in each, which can be stopped at pleasure. 

 The plants are steeped in the lowest basin for 

 two or three days, and so on successively to the 

 highest; the first basin as soon as emptied always 

 being filled again with fresh plants; at each time 

 these are supplied, the water is renewed in the 

 top basin, and the apertures being unclosed, an 

 exchange of water takes place throughout all 

 the vessels. 



It has always been supposed that some im- 

 provement might be introduced in this prelim- 

 inary part of the preparation of hemp. M. 

 Brullcs, an old curate of the department of the 

 Somme, influenced by this opinion, occupied 

 himself for several years with various experi- 



ments on the subject. Encouraged by his govern- 

 ment, he at length, in 1803, discovered a much 

 superior method, and offered it to the inspection 

 of those interested in promoting the impi-ove- 

 ment. Napoleon, in the midst of his ambitious 

 schemes and stupendous projects, still gave his 

 attention to this minute point of domestic ad- 

 vantage, and directed that trials should be made 

 of M. BruUes' plan, under the superintendence 

 of Berthollet and other scientific and competent 

 persons. These experiments were carefully pur- 

 sued for six months, and the result proved highly 

 satisfactory. 



The process is wholly different to the usual 

 water-retting wherein so much time is consumed, 

 and in which a situation near a river is almost 

 indispensably necessary for the supply of the 

 canals with soft water. This is M. Bi-ulles' pro- 

 cess: soft soap being dissolved in water it is heated 

 to nearly boiling temperature; the hemp stalks 

 are then entirely immersed in this soapy mixture, 

 the plants and fluids bearing the relative propor- 

 tion in weight of 148 to G50; the boiler contain- 

 ing the whole is then closed, and the fire extin- 

 guished. After being subjected to this macera- 

 tion for only two hours, the hemp is taken out 

 and covered witli a layer of straw, that it may 

 cool gradually without losing its humidity. 



As soon as one parcel of plants is taken out 

 of the cauldron, fresh ones are put into the same 

 water, care being taken to add a quantity of the 

 soapy mixture equal to that which had been 

 absorbed by the preceding plants. 



By then crushing and beating the fibres, they 

 were found to separate more readily than after 

 the common method of retting, and with much 

 less waste, producing in the proportion of four 

 ounces from one pound of plants, while in the 

 ordinary way only three ounces were obtained. 

 On the other hand, the utensils required, and the 

 soap and fuel consumed, might be adduced as 

 countervailing objections, which, however, were 

 believed not only by the inventor, but by those 

 who investigated the method, to be more than 

 compensated by the great advantages attendant 

 on this process. 



After watering or macerating the hemp, it is 

 sometimes dried in the same manner as flax, but 

 this operation is more usually hastened by means 

 of an oven or kiln. In this case the heat must 

 bo very carefully applied, as too great a degree 

 will injure the fibres by drying up the oil which 

 they contain, leaving them harsh and brittle. 

 Combustion is so easily excited in dry hemp, 

 that when a kiln is employed, great care is taken 

 that no fuel is used which can blaze or spai'kle; 

 coke is therefore considered most proper for the 

 purpose. 



The drying place is sometimes a kind of cavern, 

 so situated as to be sheltered from the north and 

 north-east winds, and open to the south, that it 



