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Ireland, who have a few acres to spare, would plant mul- 
berries for posterity as they do oaks, we should in a few 
years be independent of other countries for our supply of 
raw silk. 
The lettuce has been suggested as a substitute for the 
mulberry, because of its easy cultivation and cheapness ; but 
I understand, from J. D. Holdforth, Esq., of this town, that 
this plant will not answer as a general source of food, from its 
being deficient in the resinous or gummy material which gives 
strength and lustre to the silk derived from the mulberry 
plant ; and secondly, from the lettuce inducing a disease in 
the worms which proves fatal to great numbers, hence its use 
should be only occasionally resorted to, and then in small 
quantities.* With all these obstacles, however, according to 
Mrs. Whitby's report, very favourable results were arrived 
at. After making every allowance for occasional unfavourable 
seasons, and labour, machinery, outlay of money, &c, she 
found that land laid out for furnishing food for the cater- 
pillar would yield at least £20 per annum, per acre, profit. 
With regard to the rearing of the Silkworm there is little 
doubt that if we became practically familiar with their 
habits, and paid due attention to their peculiarities and 
wants, they might be reared in England as well as in any 
other country, and with as little loss by death. Equable 
warmth, throughout the period of their existence, cleanliness, 
classification, and ventilation, with adaptation of the food 
as to its maturity to the different ages of the insect, will 
ensure success. For instance, the caterpillars in their 
infancy ought to be provided with early leaves, from their 
more delicate structure, agreeing with the feeble masticating 
* Sig. Grisari succeeded, however, in feeding storms of the Bombyx 
Cynthia, the new species, upon willow leaves and lettuce leaves, and obtained 
cocoons similar to those produced from the leaves of the Castor Oil plant, 
the natural food of this insect. 
