Silk Manufacture. 85 



' According to Monsieur Nollet, the inhabitants of Tuscany, 

 especially in the neighborhood of Florence, do not cultivate 

 half as many trees as the Piedmontese, in proportion to the 

 number of silk worms reared and the quantity of silk produced. 

 This economy is realized by causing the worms to be hatch- 

 ed at two separate periods. The first brood is fed on the first 

 leaves of the spring ; and when these worms have gone through 

 their progressions, and have produced silk, other eggs are 

 hatched, and the insects are nounsiied by a seccond crop of 

 leaves furnished by the same trees. This plan is followed in 

 China, where two crops of silk are obtained in the year; 

 and it has been said that in some other parts of Asia as many 

 as twelve broods of worms are reared in the course of one 

 year. In the Isle of France Monsieur Chazal obtained three 

 generations between the months of December and May ; the 

 mulberry tree there, as well as in India, aflbrding fresh leaves 

 through the whole year. 



'Count Dandolo is of opinion that in Italy it is disadvanta- 

 geous to obtain more than one crop in each season. He 

 aflSrms that the mulberry tree cannot bear this constant strip- 

 ping of its leaves without injury. " All things considered," 

 says he, "I am well persuaded that one of our good crops 

 will be equal in produce to any number that may be gathered 

 elsewhere in a year." It is observed that the quality of the 

 silk obtained in Italy from their seccond racolta is always 

 inferior to that from the first brood of worms. 



' The Persian cultivators are accustomed, from a motive of 

 economy, to feed silk worms upon boughs of the mulberry tree, 

 instead of using the leaf separately, as is practised in all 

 temperate climates. The leaves, continuing attached to the 

 branches, remain longer fresh, have a better flavor, and are 

 more nutritious, than those separately gathered, and the silk 

 worms feed from the branches with less waste than when the 

 leaves are strown singly over them. 



'In estimating the qualities of the mulberry leaf, as regards 

 nutrition, it should be considered as being composed of five 

 different substances : the solid or fibrous, the saccharine, and 

 the resinous substances, water, and coloring matter. 



'The fibrous substance, water and coloring matter, cannot 

 be said to contribute towards the nourishment of the silk worm. 

 The saccharine matter is that which sustains the insect, causes 

 its increase in size, and goes to the formation of its animal 

 substance. The resinous substance, according to Count 

 Dandolo, is that which, " separating itself gradually from the 

 leaf, and attracted by the animal organization, accumulates, 

 clears itself, and insensibly fills the two reservoirs or silk 



