66 Mr. Murray on the Management of the Silk Worm. 



Note. — A Lira Milanese is equal to about 8d. and there 

 are 20 Soldi in a Lira M. 



The calculation, as above, includes not only interest on ca- 

 pital, but a valuation on the mulberry leaves, which is about 

 one-half of the total expence. 



The Augmentation and Diminution of the Silk Worms in 



Weight and Size. 



Increasing Progression. Weight 

 100 ova weigh about Grain 1 



After the 1st change about 15 



2d change say 94 



3d change say 400 



4th change say 1628 



5th change say 9500 



Increasing Progression. 



Size. 



The ova in the 1st instance say 1 

 After the 1st change, length say 4 

 2d change, . . 6 

 3d change, . .12 

 4th change, . . 20 

 5th change, . . 40 



Line. 



Note. — In thirty days the silk-worm has increased in 

 weight 9500 times ; and, in 28 days, the animal has aug- 

 mented in size about 40 times. 



The French Line is equal to 1.67 Lines English, calculat- 

 ing 100 Lines English to the inch. 



Decreasing Progression. 



100 Silk Worms at their greatest size weigh above 



100 chrysali weigh ..... 



100 females weigh . 



100 males weigh . 



100 females, after the ova are deposited, weigh 



100 females, naturally dead, and the eggs or ova deposited, &c. 



Grains. 

 7760 

 3900 

 2990 

 1700 

 980 

 350 



In the space of above 28 days more the silk- worm has di- 

 minished in weight about 30 times. Thus the length of the 

 silk-worm from the time of its greatest increase to the mo- 

 ment it is converted into the chrysalis, has diminished about 

 three-fifths. 



The chrysalis is the intermediate state between the worm 

 and the winged insect. 



