344 



FARMERS' REGISTER. 



means that can be made use of; and he ie besides 

 persuaded, that instead of using common stoves, 

 ihat distribute liie heat more or less irreajulariy, 

 preference should he given to JM. d'Arcet's appa- 

 ratus, which has tlie double advantage of distri- 

 buiing the heat equally in all parts of the apart- 

 ment, and to purify the air by constant ventilation.* 

 We highly approve of the views of JVl. C. Beau- 

 vais, and with him, we recommend to the grow- 

 ers of silk worms, the use of the apparatus for 

 the purpose of heat and ventilation. 



M. C. Beauvais has tried carefully to discover 

 the causes of'the diseases to which silk worms are 

 subject. His experiments have led to the disco- 

 very that many of them originate from imperfect 

 eggs, or bad stock. He insists, therefore, not only 

 on a judicious choice of the cocoons, which must 

 always be of the most beautiful and even species, 

 but he advises when the millers have left them to 

 reject all those that have any defects, and (o pre- 

 serve lor the reproduction those only which give 

 the appearance of a strong constitution. The 

 male miller according to iVl. C. Beauvais, must 

 have projecting eyes, long horns, very thick and 

 arched : wide but slender body, covered all over 

 with a glossy down ; in fine, the wings must be 

 large, and spread out. The rearer must throw 

 aside the males that have part oftheir bodies bare 

 of down, and of which the lower rings are darker 

 than the rest of the body ; above all he must reject 

 all the tuales that have short winas clipped or folded 

 up. The fiiraale must exhibit the same character as 

 the male, with this difference, that the body must be 

 wide and flexible. All females whose bodies are 

 immeasurably long, showing in each movement 

 rings without down, must be thrown away. 



The same may be said of an experiment of an- 

 other nature, which M, C. Beauvais made in the 

 spring of 1836, in rearing a certain quantity of 

 worms after the method of the Chinese. Accord- 

 ing to that method they feed the young worms 

 forty-eight times the first day they are hatched, 

 thirty times the second, twenty-four the third, and 

 twelve during the remainder of the time of rear- 

 ing. At the same time that the worms are fed in 

 this manner, they are kept in a high temperature, 

 which is from 93 deg. to 95 deg. Fahrenheit during 

 the first two stages, and from 81 deg. to 84 deg. 

 Fahrenheit during the rest of the rearing. By this 

 method the worms, according to M. C. Beauvais, 

 eat more, while they consume less leaves, because 

 they make much less litter, and the time of rear- 

 ing is shortened. That which was made in 1836, 

 at the Bcrgeries, from this process, lasted only 

 twenty-one days, and from what has been stated 

 to us, the worms evinced during the whole course 

 of their existence, a strength and vigor which are 

 not common to them in the rearing effected in a 

 lower temperature by 9 to 11 degrees, and which 

 lasts ten or twelve days longer. 



According to M. C. Beauvais, the advantages 

 which would result from a rapid rearing extend to 

 all the economical circumstances of this industry. 

 They embrace the mulberry trees, manual labor, 

 the buildings, and even the success of rearing; 

 but ali these advantages cannot be obtained ex- 

 cept the heat, dampness, and the frequent feeding, 



* See description and plan of D'Arcet's apparatus 

 at p. 77 of vol. VIII. Far. Reg. 



are in perfect harmony together, for tliese three 

 considerations are so intimately blended, that un- 

 less they perfectly accord, he does not think they 

 can succeed, and believes too, that they may ex- 

 pect greater mistakes than upon the old plan. 

 Thus the experiment of rearing silk-worine under 

 the influence of a high temperature, made by M. 

 C. Beauvais in 1831, and renewed in 1832 with 

 an excellent healing apparatus, completely failed. 

 It was only in 1836 that it succeeded, in adding to 

 the high heat continued feeding, and a certain con- 

 stant dampness. 



With a temperature of 81 to 84 degrees Fah- 

 renheit, you must keep up a moisture of 85 to 90 

 degrees of Saussure's hygrometer. 



It would, no doubt, be a very great advantage 

 if it were possible to diminish conveniently the 

 duration of the period of rearing, for it might 

 furnish the facility of attending several rearinga 

 each year, whenever a double or treble quantity 

 of mulberry trees could be had. This is what 

 your reporter has explained elsewhere. But 

 whilst we commend the generous efiorts of iVl. 

 C. Beauvais to perfect the progress of the art of 

 rearing silk-worms, your commissioners dare not 

 recommend the new method to accelerate the 

 mode of rearing to those just engaged in it. They 

 can only manifest the hope, that new and multi- 

 plied experiments will be made on that subject. 

 They ought not, besides, to allow those persons 

 occupied with this industry to be ignorant of the 

 fact of their dreading that in shortening the life of 

 the silk-worms, they should not have time enough 

 to digest, in a proper manner, the nourishment 

 they take; that the juico.s which must be identi- 

 fied with their own substance, are not sufficiently 

 perfect to facilitate the secretion of the silk, and 

 that secretion being too precipitate has not all the 

 qualifications required for the worm to spin its co- 

 coon and compose it of a thread both firm and 

 solid. 



We regret that M. C. Beauvais did not give us 

 a certain quantity of cocoons ofhis rearing, brought 

 forward by the means mentioned above, so that 

 the silk could be removed, as effected in those of 

 his common crop ; but we ought to m-ention on 

 this subject, that M. Boissiur de Sauvages had 

 already tried to rear silk worms under the in- 

 fluence of a high temperature, and that he had 

 succeeded by this method to abridge the time of 

 rearing in such a manner that it only lasted 24 

 days, instead of 36 to 40. This author states that 

 the product obtained was abundant. 



JM. C. Beauvais proposes to make this year, new 

 experiments on this method, and he has even the 

 intention of raising the temperature of the locality 

 in which he means to place his worms, so as to 

 shorten the course of the rearing, and to reduce it 

 to eighteen days, if possible. 



On this subject we shall observe that if we must 

 yield to the opinion and experience of M. Boissiur 

 de Sauvages, there is a term beyond which it is not; 

 possible to shorten the life of the worms, for the 

 period was absolutely the same in two rearings 

 undertaken in a high temperature, although, in one 

 of them the heat to which the worms was subject- 

 ed was greater by lour degrees, than the other. 

 Finally, we will express again our fear that the 

 silk produced too rapidly under the influence of 

 a very high temperature, will not have the same 

 qualities ata that raised under ordinary circumstan- 



