FARMERS' REGISTER 



8i 



apartment. If, on the contrary, the rearing wae 

 carried on in a cocoonery io which the pysiem ol 

 artificial ventilation was properly adapted, ihe 

 ■evils might he readily remedied in the following 

 manner: 



According to the observations of H. Bourdon, 

 the air which has become toiiffe, has a high tem- 

 perature, is stagnant and almost saturated with 

 moisture. To restore the air to a healthy condi- 

 tion it is necessary either to remove a portion ol'the 

 watery vapor which it contains, by lowering the 

 temperature and producing a current, or otherwise 

 by raising the temperature of the apartment n 

 little higher and giving the necessary activity to 

 the ventilation. 



In preparing my memoir upon healthy cocoon- 

 ■eries I had introduced a chupler describitig the 

 means adopted to give the current of air at all 

 times the proper degree oi'moisture. 13ut the fear 

 ofcomplicating the apparatus iieyond what was 

 •essentially necessary, induced me to suppress iliis 

 chapter, [n the heahhy cocooneries at present 

 established, there are, therefore, no contrivances 

 introduced lor directly removing any excess ol' 

 moisture from the circulating air. On the other 

 hand, as neither the use of ice or the evaporation 

 of water has been generally adopted, the means 

 iel't for reducing the temperature of the current of 

 air, are extremely inefficient. Under existing cir- 

 cumstances, it is therefore necessary, in order to 

 guard against the sad effects of the tovffe, to a- 

 bandon the means first poiiited out, and have 

 recourse to those above described. Conformalily 

 to this, the temperature of the ventilating current 

 must be raised some degrees to render it capal)le 

 of evaporating an ad<liiicnal quantity of water 

 and to increase the ventilalien, to avoid the acru- 

 mulation of vitiated air, as well as to revive the 

 silk-worms and the leaves upon which they rest. 

 By operating in this way, the desired objects, may 

 probably be attained, and the inconvenience avoid- 

 ed of being obliged to multiply the number of 

 feedings in proportion to the increased temperature 

 given to the ventilating current, in order to obviate 

 the disastrous effects of the tovffe. As to the per- 

 sons employed in the cocoonery, it is evident that 

 ihey would experience less inconvenience from 

 warm air circulating in a brisk current, than they 

 would from the tuiiffe out of doors, where the air, 

 though not quite so warm would be stagnant and 

 saturated with watery vapor. 



By way of recapitulation, I will observe, that 

 eomparatively lew of the advantages to be derived 

 from the means recommended lor the establish,- 

 ment of healthy cocooneries, have as yet been at- 

 tained. 



The means of cooling the ventilating current 

 have been either neglected, or very imperfect I3' 

 employed. The apparatus capable of carrying on 

 the forcing system of ventilation in the north ol 

 France, has, in the south, proved insufJicipnt for 

 the purpose. The power of the apparatus must, 

 therefore, be increased in warm countries, and, as 

 has been already remarked, nothing is easier than 

 to do this. 



No direct means have as yet been used to di- 

 minish the quantityof watery vapor contained in 

 the air when this becomes saturated. But every 

 ihing is ready to effect this object, if longer expe- 

 rience should show it to be indispensably necessary. 



As to the plan of raising the heat of the too 

 Vol.. VIII-11 



humid air, for the purpose of rendering it more 

 salubrious by rendering it capable of taking up a 

 Iresli quantity oi'moisture, it also can scarcely be 

 said to have had a lair trial. 



Not withstanding all these difficulties, inseparable 

 from the adoption of a new process, in so many 

 places and under such difi'erent circumstances, the 

 very advantageous result obtained in well con- 

 structed healthy cocooneries, have given them a 

 start and a progress which there is no danger of 

 seeing arrested. 



[The following additional remarks of JM. D'Ar- 

 cet are taken from the same publication.] 



Since the publication of my first m.emoir upon 

 the construction of healthy cocooneries, I liave 

 been charged with proposing the employment of 

 plans too complex and expensive. 1 can readily 

 believe that the afiparatus which I have described 

 will not be generally adopted without some oppo- 

 sition, and that to the objections already raised 

 others will be added. But the success obtained in 

 1835, in Camille Beauvais"' cocoonery, and the 

 conviction that an old manufacturer, like myseltj 

 would propose no new process, which, when laitli- 

 fully tried, would not be fcaind both practicable and 

 convenient, encourages me to look for ultimate 

 success. Besides, when we consider that the taste 

 lor agriculture is spreading among the wealthy 

 classes, that large f-apilals are already devoted to 

 thedevelopemetit of every branch of rural industry, 

 and that the sciences are put in requisition to favor 

 this happy impulse, are we not warranted in be- 

 lieving tliat the time has arrived when we can and 

 should make every effort to raise the silk culture 

 above that state ol infancy in which it has been left 

 since its introduction into Europe? I may observe 

 that liie object under consideration is not mereh' 

 the production, at considerable expense, of an arti- 

 cle of merchandise, commanding a low price, and 

 that in this respect the case is entirely difiierent 

 from what we observe in most branches of produc- 

 tive industry. A well arranged cocoonery costs 

 but little more than one of the kind ui^ually put up. 

 More att.ention is certainlj' required for its arrange- 

 ment ; but at the present day, when the march of 

 improvement has made such rapid strides, this 

 difficulty could only exist among those who had 

 not kept up with the spirit of the age. As to the 

 increase in the expenses of daily attendance dur- 

 ing the rearing, can any one seriously raise this as 

 an objection, who takes into consideration the 

 great increase of the product both as to quantity 

 and value 1 A negative answer will certainly be 

 given when it is considered that the cocooneries of 

 Europe, as ordinarily constructed and managed, 

 yield on an average only fifty pounds of cocoons 

 for each ounce of eggs, and that in an establish- 

 ment well constructed and managed, the product 

 shoukl be at least threelbid ; that the average price 

 ol the reeled silk is 60 francs per kilogramme; — 

 (about six dollars per pound,) and lastly, that 

 France has now to import annuall}' more than 40 

 millions of francs' worth of silk, which she might 

 easily raise, and the surplus, if any, command a 

 ready market in England, Russia, and the whole 

 of I he north of Europe, where the demand lor silk 

 stuffs is greatly increasing without the powerof 

 raising the raw material. These important con- 

 siderations will, I trust, put an end to the charges 



