TRANSACTIONS OF THE SECTIONS. 8? 



Notice of an Experiment on the Grotvth of Silk at Nottingham in 

 1839. By William Felkin, Esq. 



A large sample of yellow and pure white cocoons, forming a portion 

 of the results of this attempt at raising silk in England, was placed 

 before the Section of Natural History, upon the twigs where they had 

 been spun by the silk worms,— the French and Italian mode of manage- 

 ment being, so far as possible, adopted throughout the entire course of 

 the experiment. Bertizen produced equally good cocoons somewhere 

 near London, in 1790, but beyond his presenting the silk reeled from 

 them to the Society of Arts, and receiving their premium, only few 

 particulars of his experiment are known. In the present instance, the 

 food supplied to the worms spinning the white silk (owing to the 

 sudden and continued check to vegetation by severe east winds and 

 frosts throughout May 1839,) was lettuce leaves during the first three 

 weeks after hatching, afterwards they were fed entirely upon mulberry 

 leaves. Those spinning yellow silk were hatched fourteen days later, 

 and were fed from the beginning upon mulberry leaves. Of those 

 fed partly upon lettuce, 7-8ths died ; on the contrary, the greatest loss 

 in those fed altogether upon mulberry was from 30 to 40 per cent. 

 The average of loss upon the continent of Europe is from 35 to 

 60 per cent., the latter being the usual loss under the management of 

 the peasants. That division of these yellow ones which spun first, 

 and which were most healthy, experienced a loss of only 10 to 20 per 

 cent. The loss in China, owing to their superior skill and care, is 

 often not more than 1 per cent, of those hatched. The hatching in 

 question was of eggs procured fi-om Italy ; and this, as well as all the 

 subsequent processes of feeding and spinning, took place in a ware- 

 house in the centre of the town of Nottingham, amidst the usual noise, 

 dust, and activity of a wholesale business in cotton goods, where the 

 air must have been in some degree tainted by the oily matters used in 

 their fabrication. The weather for three weeks from the 14th of May 

 was dry, but piercingly cold ; then, after an interval of two weeks of 

 fine weather, there was constant and most unusual humidity, so that it 

 was almost impossible to refresh the air of the apartment, or avoid 

 giving the food in a damp and heated state ; especially as, from the 

 number of worms (about 10,000), much difficulty was expeiienced in 

 obtaining mulberry leaves in sufficient quantity for their use, these 

 having to be collected from places in some cases 50 or 80 miles di- 

 stant. Such was the continuance of rain in July, that the largest flood 

 occurred ever remembered at that season of the year. To suit our 

 variable climate the temperature of the room was from the first kept 

 low, varying from 70 to 55 degrees. Altogether, the circumstances 

 under which this experiment was made were very unpropitious. 



In addition to the usual diseases which Mr. Felkin had observed, 

 when formerly investigating the French and Italian management of 

 silk worms, one occurred immediately after a violent storm of thunder, 

 lightning and rain, which was quite new to him. The worms were 

 nearly ready to spin, and those affected were found dead or dying ; the 



