228 Progress of Invention. 



rapid production of the cocoon. This promises to open a new and 

 profitable branch of industry for Ireland and other portions of the 

 British dominions. The Ailanthus, upon the leaves of which the 

 silkworm feeds, thrives well in this country, and has already been 

 introduced largely into France. It grows rapidly, and its wood is 

 of the very best description for any industrial purpose. The young 

 worms require to be kept in the house for a few days after having 

 been hatched ; and at every period of their existence they require 

 moisture. The silk, though an excellent textile material, is not 

 equal to that obtained from hot countries ; and some difficulty has 

 been experienced with the process of winding it, since, as the 

 cocoon is open at one end, it will not float in water ; and, having 

 no gumming matter, it affords only spun silk. It is, however, easily 

 bleached, and it takes dyes extremely well. 



Substitutes for Ivory, etc. — An excellent substitute for ivory, 

 bone, horn, etc., may be obtained by cutting caoutchouc or gutta- 

 percha into small pieces, after it has been thoroughly washed, and 

 then dissolving it in well-closed vessels with chloroform, or some 

 other solvent. When the solution is complete, chlorine is passed 

 into it, until the whole assumes a bright yellow tint : after which 

 the product is to be wasted well with alcohol. It is then to be 

 augmented in bulk by means of a small quantity of chloroform and 

 agitating ; and chalk, oyster shell, marble, heavy spar, allumina, or 

 sulphate of lead, in the state of fine powder, is to be added, to an 

 amount dependent on the density and tint which are required. 

 Having been kneaded, the mass is to be formed into blocks of a size 

 suited to the purpose for which they are intended, and subjected 

 to pressure. The result answers well for buttons, knife-handles, 

 etc., and may be cut, turned, and polished in the same way as ivory. 



Catalytic Action of Potatoe-peel, etc. — Schonbein has recently 

 discovered that catalytic power is not confined to diastase, gluten, 

 saliva, and a few other organic substances, but is very generally 

 diffused through the animal and vegetable kingdoms, and is 

 possessed in a very remarkable degree by potatoe-peel, lettuce, the 

 root of dandelion, etc. So effective is potatoe-peel, that if kept for 

 ten or twelve hours with starch, at a temperature of from 45° to 

 50° Cent., the starch will all be changed into sugar. 



New Method of Removing Hair from Hides. — The ordinary 

 method of removing hair from hides is tedious and troublesome, and 

 leads to considerable loss from abrasions of the hide. These incon- 

 veniences have been obviated by a process which has been recently 

 invented. The hides are placed in a close chamber, in which water 

 is violently scattered about, so as to be brought into such a state of 

 minute division, and form a species of vapour, which, no mode of 

 escape being afforded to it, enters into the pores of the hides. 

 In a few days they become so soft, that the hair may be removed 

 so easily that three times as many skins may be deprived of it 

 in a given time, as by the usual method, and without the smallest 

 tendency to putrefaction, or injury to the skins. The rapidity of 

 the process depends on the minute division of the watery particles, 

 the closeness with which they are brought into contact with the 



