CHAP. C. UllTlCA^OEM. AfO v RUS. 1357 



spirit?, the gum having been dissolved by the spirit. The whisk is then moved lightly about till 

 tlie filaments adhere to it, and are drawn off. As soon as a sufficient number are collected, the 

 reeling begins. (SeeAmer. Silk-Grower's Guide, Murray on the Silkworm; Nouv. Cours d'Agric., &c.) 

 If well fed, in a proper temperature, the caterpillars will have finished their labours in 24 days from 

 the period of being hatched ; and the quantity of silk produced will, other circumstances being 

 equal, be in proportion to the quantity of food devoured: its quality will depend on the climate and 

 soil in which the leaves have been grown. An ounce of eggs will produce about 10,000 caterpillars, 

 which will consume 1073 lb. of leaves, and produce 80 lb. of cocoons, or about 8 lb. of raw silk. The 

 worms are subject to numerous diseases, the most fatal of which is vulgarly called the tripes ; and 

 is brought on by wet or improper food. When any insects appear sick, they should be immediately 

 removed from the rest, as all their diseases appear to be contagious Wet leaves should never be 

 given to silkworms, as they occasion disease ; and it is better to let the insects fast for 24 hours, 

 or even longer, than to give them leaves that are not perfectly dry. In wet weather, the branches 

 of the tree should be gathered, and hung up in a dry place ; or the leaves should be gathered, and 

 spread out to dry. {Nouv. Cours d'Agric, vol. xvi. p. 103. ) 



Substitutes for Mulberry Leaves in feeding the Silkivorm. It is probable that the leaves of all the 

 plants that contain a milky juice will, if they are eligible in point of texture, afford suitable food 

 for the silkworm, from the common property of milky juice, that of containing caoutchouc. 

 Accordingly, trials have been made with the tender leaves of the tig, with the leaves of the maclura, 

 and of /Tcer platanuides and A. tatftricum, among trees ; and of lettuce, endive, beet, spinach, nettle, 

 Sec, among herbaceous plants. None of these substitutes, however, are of any real use, unless we 

 except the maclura and the lettuce. The former, according to the American Gardener's Magazine, 

 is thought likely to answer to a certain extent ; as the lettuce and endive have done formerly, more 

 especially when the plants have been allowed to send up their flower stalks before their leaves were 

 gathered. In 1792, a Miss Croft of York sent a specimen of silk of her own rais ng to, the Society 

 of Arts, the worms producing which had been fed entirely on lettuce leaves. 



Soily Situation, Propagation, and Culture. The white mulberry is more 

 tender than ilforus nigra, and requires more care in choosing a situation for 

 it. Calcareous soil is said to produce the best silk ; and humid situations, or 

 where the roots of the tree can have access to water, the worst. A gravelly 

 or sandy loam is very suitable; and trees grown on hilly surfaces, and poor 

 soils, always produce superior silk to those grown in valleys, and in rich 

 soils. The tree is propagated by seeds, cuttings, layers, and grafting. To 

 obtain seeds, the berries must be collected from trees which have been 

 known to produce male catkins the preceding spring. The berries are 

 either gathered when quite ripe, and left to become dry before the seed 

 is separated from them ; or they are put into water as soon as gathered, 

 and rubbed so as to separate the seeds, which are cleansed from the pulp 

 in the water, and then rubbed dry on a linen cloth, and either sown im- 

 mediately, or mixed with sand, and kept till wanted for use. In the south 

 of France, the seeds are sown as soon as the fruit is gathered, and the plants 

 come up the same autumn ; but, in colder climates, they are kept till spring, 

 when they generally come up in three or four weeks, and require some pro- 

 tection, at first, during cold nights. In Germany, and in the north of the 

 United States, the young plants are covered, during the first winter, with dry 

 leaves or straw ; and this covering, or mulching, is continued on the ground 

 for three or four years, till the plants are thoroughly established, to protect 

 their roots from the cold. The young plants are generally taken up and 

 replanted the second spring, care being taken to place them in rows 4 ft. 

 asunder, for the convenience of gathering the leaves. M. a multicauiis is always 

 propagated by layers or cuttings ; the layers being made in spring or at mid- 

 summer, and separated from the mother plant in autumn ; or by cuttings of 

 branches, or truncheons, which will root readily, and produce leaves for the 

 worms the following year. Count Dandolo recommends grafting the species 

 with the large-leaved varieties, near the ground, the third spring; but most 

 writers on the silkworm appear to prefer seedling plants, or plants raised 

 from layers or cuttings, to grafted ones. In pruning, cutting in, or heading 

 down, the trees, the great object is to preserve the equilibrium of the heads, 

 so that the sap may be equally distributed through the branches on every 

 side. On this depends the production of a crop of leaves of equal quality on 

 every part of the tree, which is alike important both for the first crop, which 

 is given to the worms, and for the second crop, which is required for the 

 nourishment of the tree. 



Insects and Diseases. The leaves of the white mulberry are eaten by no 

 insect but the silkworm : it is, however, attacked by numerous diseases, partly, 

 no doubt, occasioned by the unnatural manner in which it is treated, by being 

 stripped of its leaves. One of these diseases is brought on by any sudden 



