618 



FARMERS' REGISTER. 



the air corrupt and stagnant to a tlegrce that im- 

 peded respiration, disairreeable effluvia disiruised 

 with aromalics, the wickers too close together, co- 

 vered with lernienling litter, upon wliich the silk- 

 worms were spinning. The air was never renewed 

 except hy the breaclus vvliich time had worn in the 

 doors anil windows; and that which made this seem 

 more sad and deplorable, was remarking thai the 

 persons wlio atiended to these insects, however 

 healthy they miglu have been when they entered 

 on the employment, lost their heahh, their voices 

 became hollow, their hue pallid, and they had the 

 appearance of valetudinarians, as if issuing from 

 the very tombs, or recovering iiom some dreadful 

 illness."— (page 303.) 



" The silk-worms succeed better in the great la- 

 boratory, and form finer cocoons. 



"The total result will show that the great labo- 

 ratory is less expensive, and better overlooked, 

 consumes less lealj preserves the worms better 

 from the attacks ol' disease, and atlbrds an abun- 

 dance and fine produce of cocoons." M. Dandolo 

 observes, that having reared silk-worms, in large, 

 middle-sized, and small laboratories, the cocoons 

 of the large laboratories were invariably of supe- 

 rior quality. "Neither is it liable to breed so 

 great a quantity of carbonic acid gas, or mephitic 

 air, so peculiarly noxious to the silk-worm, as the 

 email laboratory." — (Note, page 298.) 



I have recently ascertained that the mortar or 

 lime from an old building, when used as a surface 

 dressing, will produce a growth of white clover. 

 In the spring of 1838 a cart load of this compost 

 was thrown on a piece of land that produced no- 

 thing but hen's nest grass, and a very feeble 

 growth of that ; in June last a beautiful growth of 

 white clover covered the spot whence the compost 

 had been shovelled ofi and applied lo some trees 

 a few steps distant. When 1 wrote you some 

 time ago on the subject of marling this spot was 

 overlooker!. Layton Y. Atkiks. 



POSTSCRIPT. 



Among the causes which have contributed to 

 friilure, in many ol the atteinpts to rear silk-worms 

 during the past summer, the retarding the hatch- 

 ing of eggs by ice-housee, or otherwise, may be 

 named. The cause, however, of disease, must be 

 Bought for in the manner of retarding, or in the 

 circumstances of the eggs, either belbre or after 

 they were subjected to the process. U] for exam- 

 ple, eggs had been placed in a relrigerator or ice- 

 house in January or February, and the package 

 containing the eggs was opened frequently in 

 March, April and May, for the purpose of with- 

 drawing portions lor hatching or lor sale, the con- 

 dition of the remaining eggs would be changed by 

 the sudden inlroduclion of the atmosphere, so as 

 to render it dangerous lo subject thein again lo 

 the full operation of the retarding process. My 

 experiments, made the present season, prove that 

 prrgg may be safisly retarded until late in June, 

 full two months beyond the natural period lor 

 hatching. Tiiis period, in Virginia, in latitude 38°, 

 varies I'rom the 20th of April until the ISlh of 

 May. In 1836 it occurred the 5th of May, in 

 1338 \5\h of May, in 1839 5th of May, and in 

 1840 20ih of April.* 



* Those periods were ascertained by leaving eggs 



If the win'er state of the eggs may be prolong- 

 ed until the 20th June, I think it fair to inler that 

 it may be extended to July or August. Mr. 

 McLean, of New Jersey, has succeeded in re- 

 tarding the eggs until the last named periods. But 

 this is an important subject, and time, wvh oft-re- 

 peated experiments, alune must furnish facts on 

 which pos/Z(t"c conclusions may be based. In the 

 mean time a free communicaiion ol' facts and opi- 

 nions from persons engaged in rearing silk-worms 

 is very desirable. 



There is another cause w! ich I believe has 

 produced numerous iailures in attempts to rear 

 late broods of silk-worms, which deserves no- 

 tice. In all early rearings it is well known that 

 the worms and the leaves of the mulberry ad- 

 vance s/mw//ancoiis/i/ towards maturity; and hence 

 the worms have leaves suited to their different 

 ages. But in many case?, when late rearings 

 have been attempted, the leaves have been fed 

 to the worms promiscuously, and consequently the 

 young worms have been compelled to eat leaves 

 not containing the kind of" nourishment suited to 

 their delicate organs when first hatched. I know 

 it has been asserted that the young silk-worm will 

 devour voraciously the toughest leaf; but because 

 the worms will eat such leaves to escape starva- 

 tion, it should not be inferred that it does no harm. 

 A little reflection, I think, should convince us that 

 it is unreasonable and unnatural. 



The following quotation from an article trans- 

 lated from the French, and published in the Farm- 

 ers' Register, lends to confirm the opinion express- 

 ed above. 



" On the other hand, if the putting forth of the 

 leaves is backward, and it is followed by heat 

 that lasts long, as may usually be expected, and 

 yet if but little heat is kept up in the laboratory, 

 the worms will advance slowly and their growth 

 will be prolonged. Still the leaves grow and be- 

 come harder, and have too much consistence for the 

 worms, in their backward state.'''' This, then, is a 

 state of things in which the growth of the worms 

 should be hastened by continued high temperature, 

 in order that their progress may be brought up to 

 that of the leaves, which is an essential point." 



I will only add that the object of the French 

 writer may be obtained without raising the tem- 

 perature, or without the use of artificial tempera- 

 rature at all, viz.: by selecting the most lender and 

 succulent leaves lor the first ten days, reserving 

 the toughest lor the last age. 1 have pursued this 

 course lor Jit-e years, and have only had one late 

 rearing that was diseased. 



The hatching of silk-worms' e^gs had been re- 

 tarded until first of August in Italy, prior to the 

 year 1778, and consequently is not a discovery of 

 American ingenuity. The discovery was of no 

 use to them, because the rearing of late broods 

 was prohibiteu by the government, to prevent the 

 destruction of the mulberry trees. (See Farmers' 

 Register, vol. vii. p. 274.) 



exposed to all the changes of the weather, in our co- 

 coonery during each preceding winter, with the excep- 

 tion of 1836. The eggs for that year had been kept 

 in an upper room in Fredericksburg. 



