PRACTICAL FARMER 



(From the New England Farmer.) 

 SILK Ctll-TURE. 



(Coricluded.) 



V/e Fiave .=een that one ounce of seed contains 

 42,000 worms; M. Beauvais employed 8 ounces 

 of seed ; lie ought, therefore, to have had 336,000 

 silk worms. 



He obtained and realised 1,102 pounds, or 551 

 kilogr. of cocoons ; it requires at the Bergeries 

 but 360 cocoons to make a pound, he has, there- 

 fore only brought to a productive state 286,520 

 silk worms. He lost 4000 at the mounting, by a 

 fault in the arrangement of the bruyeres (brush- 

 wood,) ventilation having been nearly suppressed 

 in arranging them. He lost, therefore, in the first 

 ages, 45,480 including the eggs which were not 

 hatched. 



It results from an analysis which M. d'Arcet 

 has communicated to me, that the air in the estab- 

 lishment of the Bergeries, during the fourth age, 

 ajjpeared to be slightly alkaline. Water which 

 was condensed in it, {)y meaiis of a balloon f.lled 

 with ice, was found to be as limpid as distilled 

 water — it was slightly alkaline; the nitrate of sil- 

 ver did not fornj a precipitation at the moment of 

 mixture; but very soon it became endued with a 

 pale red. At this period of the process, ventila- 

 tion was very regular; the air was so little changed 

 that carbonic acid could not be found by means 

 of the water bath, and that the eudiometric ex[>er- 

 iments made with the air by this water bath, 

 whether by phosphorus, or the deutoxide of nitro- 

 gen, always indicated as much nitrogen and oxy- 

 gen in it, as in the air taken from out-doors and 

 comparatively essayed ; this air contained only 

 sligiit traces of ammonia and carbonic acid com- 

 bined. 



At the period of mounting, ventilation, as I 

 have said, was interrupted, and in part suppressed 

 by the arrangement of the bruyeres ; and at this 

 time, tlie air in the establishment had ceased to 

 be as |»ure. M. Henri Bourdon, who three times 

 analyzed it, found it to be composed in the hun- 

 dred for a medium term, of 



Nitrogen and carlwnic acid, 82,57 



Oxygen, 67,43 



100,00 

 The atmospheric air, we know, coutains in the 

 hundred, 



Nitrogen, 79 



Oxygen, 21 



It will be seen that this air was already much 

 vitiated. At this period, the water condensed by 

 means of ice in the estabilshment, was limpid ; it 

 had neither taste nor smell ; it was alkaline ; it 

 was not disturbed by the addition of nitrate of 

 silver; but it almost immediately became colored 

 with a deep brownish red, an abundance of which 



was at once precipitated, but which does not 

 appear to have been [)erfectly defined. 



We can imagine what would happen to worms 

 kept constantly in an establishment not ventilated, 

 from the following experiment which M. d'Arcet 

 made with worms which had been bred in pure 

 air. Twelve large silk worms, taken in the fourth 

 age, were enclosed in a quart bottle, into which 

 mulberry leaves had been put at the end of 

 twentyfour hours, the air contained in this bottle 

 had diminished in volume ; it was alkaline, and 

 contained in the hundred, 



Nitrogen, 79,11 



Carbonic acid, 16,50 



Oxygen, 3,39 



100,00 



This air was, therefore, almost completely 

 vitiated. Of the twelve silk worms, one was 

 dead ; the others which were still alive, were 

 drawn up, of a dingy yellowish color, almost 

 motionless ; three others died soon after upon 

 fresh leaves; the other eight consumed a little; 

 three made a little silk before they died, two were 

 converted into chrysalis without spinning, and 

 three died without sj)inn:ng. and without being 

 converted into clirysalis, 



I have before stated that ]\I. Beauvais ought to 

 have had 336,000 worms. Out of one Imndred 

 eggs, he has, therefore, realised 85,27 cocoons ; 

 and lest 1473 silk worms and eggs not hatched. 



By adding to the 286,520 worms which sjjun, 

 the 4000 which died at mounting, we have 290,- 

 520 worms, as the result of the process. The 

 worms had eaten 16,830 pounds of leaves ; the 

 fresh leaf contains in the hundred — Dry leaf, 32; 

 Water, 68. Each silk worm, therefore, had eaten 

 in the whole course of his life 29 gravimts of fresh 

 leaves, the s;ramme is equivalent to 15,434-1000 

 grains Troy. 



I have before spoken of pupils. M, Beauvais 

 represents himself as a man of conviction and of 

 progress ; but this conviction and progress his 

 ardent and disinterested zeal %eeks to give weight 

 to and extend, in a manner which indefinitely 

 increases their influence. To attain this object, 

 he has oj)ened gratuitously at liis establishment 

 theoretical and practical courses of instruction, 

 which are attended by young proprietors coming^ 

 from all parts of France, This year the number 

 of fifteen were attracted to them. Among them 

 were found, with M. H. Bourdon, pupils of Ro- 

 ville, the marquis Amelot; a large proprietor in 

 Gatinais ; the son of the baron Mallet; M. Bella, 

 son of the director of the model farm of Grignon ; 

 M. Baynard, former prefect of the Hautes-Alpes 

 and of Maine-et-Loire, who is at the present time 

 nuking considerable plantations of mulberry trees 

 near the Bergeries. After having employed a 



