lY^. on silk worm's. Oct ^* 



fully to 'prove the practicaTiility of nouri/lung silk 

 worms entirely upon lettuce, if they be kept in a 

 •warm enough temperattire of the air, while on that 

 food ; indeed it appears that these worms not only li- 

 ved upon lettuce, but even preferred it to mulberry 

 leaves. 



This fact being establifhed, it next will be necefsa- 

 ry to ascertain which kinds of lettuce answer the 

 purpose best. There are about thirty kinds usual- 

 ly sold in the seed Ihops, which differ very much 

 from each other. The tenderest appears to me to be 

 that called Spanijh montree^ and next to that the ke^ 

 or cojs lettuce when, cabbaged. This last would pro- 

 bably resist rain the best. If any person wiflies to 

 make a comparative trial of all the kinds, at, the pro- 

 per season of the year, I fhall endeavour to procure 

 the seeds for them, if they have no other opportuni- 

 ty of obtaining them. 



As we now see that the silk worm eats lettuce, and 

 thrives upon it in proper circumstances, it is by no 

 means impofsible but other kinds of food may be 

 found which will answer the same purpose. I re- 

 commend the chicorium as a proper plant for trial. 

 The chicorium intyhm is, like lettuce, a lactescert 

 plant ; the common endive is also of the same clafs. 

 There is nothing unusual in the circumstance of a 

 certain degree of heat being required to make ani- 

 mals thrive, when kept upon a particular kind of 

 food, that could be dispensed with if they were fed 

 on another sort. Farmers now begin to learn, from, 

 •experience, that bullocks fed upofi turnips, if kept 



