22 On the Prevention and Cure of 



The oxygenated muriatic acid, recommended as the 

 most quick and powerful in its effects, was that which 

 he employed in preference, without being prevented by 

 the fear of its action being too powerful upon them ; he, 

 however, regulated the doses. 



It was in the month of April, year 10th, that Paro- 

 letti made his first experiments, in a village near Turin. 

 He was informed that, in one of his rooms (which re- 

 ceived, the air from two windows only, exposed to the 

 south), the Silk- Worms which had passed the fourth 

 change had become feeble, and refused the leaf; that 

 many discharged their excrements in a liquid glutinous 

 state and olive-coloured; that others had some red spots 

 on the skin ; that many died ; that their dead bodies be- 

 came hard, were covered by a mould like cotton, and 

 assumed the appearance of a piece of chalk. The dis- 

 ease made a rapid progress; the symptoms became 

 worse ; the Worms, which, in the beginning, had some 

 small red spots on them, lost by degrees their natural 

 colour; the dead bodies were black, and passed 

 quickly to a state of putrefaction. 



Such was the state of the disease when M. Paroletti 

 prepared himself to save these families by fumigation. 

 He mixed, in a small glass vessel, one ounce of the 

 black oxide of manganese powdered (three decigramme), 

 on which he poured some nitro- muriatic acid, and mixed 

 it with a glass spatula ; the oxygenated acid gas produced 

 a lively agreeable odour ; he caused the fumes to pass 

 through all the angles of the room ; occasionally pour- 



