M. TECHNOLOGY. 571 



camphor had been placed, and on the crevices of which 

 paper had been pasted. Although the transportation, with 

 the greatest dispatch, occurred at a season of the year when 

 the temperature was favorable to the metamorphosis, upon 

 opening the box, several weeks after its arrival at its des- 

 tination, not a single butterfly was found ; all the cocoons 

 were perfectly sound, and the worms had assumed mummy- 

 like properties, were black and hardened, and occasioned 

 no stain of any kind. Practically, no appreciable amount 

 of camphor had been volatilized. This experiment certain- 

 ly shows that this method of transporting cocoons merits 

 consideration. 



The great defect ^in the processes for unwinding the co- 

 coons, which in so many ways afiect the quality and quantity 

 of the product, lay in the necessity of employing water of 

 a high and uniform temperature, originally maintained by di- 

 rect application of fire, but since 1810, indirectly, by use of 

 steam. In the last two or three years, Limet, a manufac- 

 turer of Cosne, introduced a new process, involving the alter- 

 nate and also combined use of steam and water. By one 

 stop-cock steam is first admitted, in order to soften the co- 

 coons; by opening another, they are then saturated with wa- 

 ter ; in this condition they would sink ; but, by opening a 

 third stop-cock, the water is forced out by the pressure of 

 the steam, the cocoons swell and float again, and the unwind- 

 ing is accomplished with the greatest ease. The quality of 

 the silk is improved in many respects, the amount of waste 

 diminished, and labor economized. 6 C ^ Septemher 5,1872, 

 353. 



PRESERVATIOX OF HAIRS FOR THE HATTER. 



A method of treating animal hair for the uses of the hat- 

 ter, Avhich has been kept secret for a long time, is now known 

 to consist in the application of a solution of the nitrate of 

 mercury for the purpose of preventing the putrefaction of the 

 fibre. This substance, however, is known to be very delete- 

 rious both to the health of the workmen and to the imple- 

 ments of the trade ; and, quite recently, carbolic acid or creo- 

 sote has been used to great advantage as a substitute. This 

 has the property not only of preserving the animal matter, 

 but of causinsj the hairs to contract, thus renderinsr them 



