142 THE LIFE OF AN INSECT. 



consumed, every year, not less than five million 

 pounds of raw silk. By means of very accu- 

 rate experiments, it has been ascertained that, 

 in order to procure one pound of raw silk, we 

 must have twelve pounds of the cocoons spun by 

 these larvae. In order to produce twelve pounds 

 of cocoons, one hundred and ninety-two pounds of 

 mulberry-leaves must be eaten up ; or, which is the 

 same thing, for every pound of raw silk, we have 

 to supply to the worms one hundred and ninety-two 

 pounds of leaves. We can now leave the calcu- 

 lation in the reader's hands ; but we may mention 

 the sum total : it is, that for every year's consump- 

 tion of raw silk by our country, there is a certain 

 consumption of ninety-six millions of pounds of mul- 

 berry-leaves ; and as one hundred pounds of leaves 

 are calculated as the produce of one tree, it follows 

 that nine millions six hundred thousand mulberry 

 trees must grow, in order to supply food to the 

 silk-worms necessary to furnish Great Britain with 

 silk for one year. Let us add, that this five mil- 

 lion pounds of raw silk is the production of the 

 inconceivably great number of eighteen thousand 

 million silk-worms. The Count Dandolo, who has 

 written an excellent treatise on this subject, in 



