274 



FARMERS' REGISTER, 



[No. S 



are old, that spread seven or eight yards across. 

 Vicenza. — The produce oC silk amounts here to 

 about 6 liv. the campo, over a whole farm ; this is 

 about 3a. an acre. The sacco of leaves weigh 

 75 lb. and forty sacdii are necessary for one ounce 

 of seed ; which gives 100 lb. of cocoons, and 10 lb. 

 of silk. One hundred ireen, of twenty years old, 



J^ield forty sacchi j price 3 liv. to 11 liv. : conimon- 

 y 3 liv. Price of cocoons SOs. to 50s. the pound. 

 I was glad here to meet with some intelligence 

 concerning the new silk worm, said to have come 

 .from Persia, which they have had here eight years, 

 but is in the hands of so lew persona, that I could 

 get none of the seed ; and I suspect that it is lost ; 

 lor, on repeated inquiries, I was referred to other 

 parte of Italy. While they had this worm, they 

 had four crops of cocoons a year: — 1. In tlie be- 

 ginning of June. 2, The end of the same month. 

 3. The middle of August. 4. In October. This 

 worm is essentially different flora the common 

 ones in the circumstance of hatching; no art will 

 hatch the eggs of the common sort the first year, 

 that is, the year of the flies dropping them; they can 

 be hatched the year following only ; but of this 

 new sort, the eggs will hatch in fifleen days the 

 same year, if they be in the proper heat. But it is to 

 be observed, that they use this sort of worm not re- 

 ally to command several crops in the same year, for 

 mulberry trees will not bear it without destruction; 

 but merely as a succedaneura to the common sort 

 of worms, if by frosts in the spring they be lost for 

 want of food ; this new sort is in reserve, to apply 

 the leaves to profit once in the year. Theoretically 

 the plan is good ; but there must have been some- 

 thing in practice against it, or we may conjecture 

 that afler many years the use of them would have 

 been generally introduced. 



This will not be an improper place to introduce 

 eorae remarks on this subject, by an author 

 much esteemed, but quite unknown" in England. 

 It appears from the work of Count Carlo Bettoni, 

 of iirescia, that the discovery of the new silk worm 

 arose from experiments made with a view of find- 

 ing out a cure for the sickness of mulberry trees, 

 called moria ; this was supposed to arise from strip- 

 ping the leaves in the spring annually ; it was 

 thought, that if some means could be discovered 

 of postponing the gathering much later in the year, 

 it would greatly fiivor the vegetation and health 

 of the trees ; an effect that could only take place 

 by means of a worm that would hatch much later 

 than the common one. In 17G5, a second hatch- 

 ing of the eggs of the common worm is said, by 

 the same author, to have been made ; part of 

 which were ted with the second growth of leaves, 

 and part with the leaves of trees that had not 

 been gathered in the spring. Those fed with 

 the old leaves gave a greater number of cocoons, 

 and of a better quality than the others. Those 

 experiments were repeated by many persons ; and 

 it was found, that in the heats of July and Au- 

 gust the worms vvoulil not do well; but in Septem- 

 ber much better, and that the trees did not suffer 

 from having their leaves gathered in September. 

 The same author says, that the new worms 

 (which he caUsforestieri) will hatch three times 

 a year, and that no art will prevent it ; no cellars," 

 no cold, will keep them from if, though it may re- 

 tard them some time,as he tried in an ice-housij, by 

 which means he kept them inert till August. But, 

 on the contrary, the common sort cannot in general 



be hatched a second time the same year, even with 

 any heat that can be given; yet he admits, that 

 they were hatched by certain persons in 1765, 

 The nevv ones sleep four times, like the common 

 ones, but begin to spin their cocoons five or six 

 days sooner : they eat less in quantity, but gives 

 lels silk ; and as this defect is balanced by the ad- 

 vantage in food, they ought not, says the Count, 

 to be proscribed. Their cocoons are small, but 

 the consistency is good and fine ; and their silk ia 

 fine, and softer than the common : he sold it lor 4 

 liv. or 5 liv. a pound more than common silk. 

 There is however, an evil attends them, which ia 

 the uncertainty of their hatching the second and 

 third time ; sometimes all the seed will hatch, but 

 at others only a part ; even only the seventh and 

 tenth of the quantity : but the first hatching is re- 

 gular, like that of the common worms. A cir- 

 cumstance in the courae of his trials deserves 

 noting, that he found the worms of both the old 

 and new sorts would drink water when offered to 

 them, and that the cocoons were the larger lor 

 their having had the water. 



They have had a sort in Tuscany that hatches 

 twice a year; and the Count writing thither for 

 information concerning them, found that their silk 

 was coarser than the common, and of lefs value; 

 and he judges them to be a difierent kind from hia 

 own, which hatches three times. The Count 

 concludes nothing determinate concerning them ; 

 but resolves to continue his numerous experiments 

 and observations. As there may be persons who 

 think, as 1 did at first, when I heard of this sort 

 of worm, that if any succeed in England it would 

 probably^bc this. It is proper to observe, that Count 

 Bettoni had nothing in view but the diseases of 

 the mulberry trees, and does not seem to have had 

 at all in contemplation the evils attending late 

 frosts depriving the worms of their usual food ; 

 and if the common sort may be retarded in hatch- 

 ing (which, he shows) till August, equally with 

 the new sort, there docs not seem to be any ex- 

 traordinary advantage in this sort, for a northerly 

 climate, more than in the others. The Count's 

 book was printed at Venice in 1778. 



Sig. Pieropan has made an observation, which 

 deserves noting ; mulberries, and likewise other 

 trees are generally found to succeed much better 

 when grafted a little before sun-set than at any 

 other time : the reason he attributes to the heat 

 of the earth after sunset ; he kept ajournal some 

 years, of the comparative heat of the atmosphere 

 and the earth, at the depths of four, twelve, and 

 tvventy-ibur inches ; and has found, that immedia- 

 tely after the setting of the sun the mercury in 

 those thermometers under ground had always 

 risen some degress gradually till the rising of the 

 sun, when it as regularly falls. 



The following is Iha Jlccount of the Profit and 

 Loss of Six Ounces of Seed, for Three Years, 

 at Vicenza, by Sig, Carlo Mudena. 



1778. 



Expenses. liv. s. den. 



Semenza — seed, 6 oz. - - 36 



/^ogZt'a— leaves, 26,475 lb. - - 1545 4 

 Spesa — gathering leaves and at- 

 tendance, - . - - 866 16 

 Filnrc — ^spinning 992 lb. cocoons. 



