certain Diseases of the Silk -Worm. 21 



Department of Siena ; it was inserted entire in the se- 

 venth number of the Biblioteca Italiana ; and also no- 

 ticed in the Italian Journal, Sunday, October 30th, 

 1803 ; a very similar account may be found in the 

 Bullettino della Societa Felomatica of the month A'i- 

 vose : the importance of its object obliges us to present 

 an account of it. 



The author, born in a country where Silk-Worms 

 form one of the principal branches of the produce of 

 the husbandman, and who has applied himself parti- 

 cularly to this part of rural economy, observes, that 

 there are, in some years, unforeseen events, which de- 

 stroy, in a few days, the hopes of the cultivator. Expe- 

 rience having convinced him, that frequently the viti- 

 ated state .of the air in the rooms, in which Silk- 

 Worms are reared, was the most common cause of their 

 diseases, attracted his attention to the means of renew- 

 ing the air, and destroying the deleterious gas with 

 which it was charged. The custom of lighting fires in 

 the rooms, of burning perfumes, of the exercise of ven- 

 tilators, appeared to subject them to some of the most 

 grievous inconveniences, by destroying the uniformity 

 of the temperature, so necessary to their progress to- 

 wards perfection ; and the odour of the greater part of 

 the plants which were burnt incommoded them. The 

 success which he had obtained in many instances by 

 the immersion of the diseased Worms in vinegar in- 

 duced him to employ the method of Citizen Guyton 

 Morveau for purifying the air; viz., the fumes of the 

 mineral acids. 



