138 [Senate 



off in proportion to the quantity of food consumed, was about equal 

 to that ascertained to escape from a healthy man. 



I found from the most carefully conducted experiments that the 

 weight of 100,000 silk worms, about five days before winding was 

 four hundred and fifty-eight pounds, and that they would consume 

 daily 372 pounds of leaves ; * and that their increased weight in 

 twenty -four hours, from the food consumed, was 46 pounds ; and that 

 the enormous amount of 206 pounds was given off in the same time 

 in the form of exhalations or imperceptible perspiration alone. 



This, then, I think, fully explains the cause of the disease com- 

 plained of by many, and establishes the importance of ventilation in 

 every possible form. 



In the corner of the building there should be a hatching room, 

 with which the furnace below should be connected so as to receive 

 a greater or less degree of heat as may be required, without refe- 

 rence to the temperature of the feeding rooms. 



Fixtures. — In fitting up the hurdles, or feeding shelves, for a 

 building of twenty feet wide, it will require a double range of posts 

 2 J or 3 inches square, each side of the centre of the rooms run- 

 ning lengthwise, and the length of the shelves apart, in the ranges, 

 and each two corresponding posts, crosswise of the ranges, about the 

 width of the two shelves apart. On each double range across these 

 posts, are nailed strips one inch or more in width, and about fifteen 

 inches apart, on which the trays or hurdles rest, which may be 

 drawn out or slid in from their respective passages as may be found 

 necessary in feeding. The aisles or passages of a building of the 

 above width, will be four feet each, allowing two feet for the widA 

 of each MTi^^e hurdle. 



The hurdles that I have used for many years are of twine net 

 work. A frame is first made five feet long and two feet wide, of 

 boards I of an inch thick and 1| inches wide. There should be two 

 braces across the frame at equal distances, five-eighths by seven-eighths 

 of an inch square. On a line 2ihoViihalfan inch from the inner edge of 

 the frame, are driven tacks nearly down to their heads at such distances 

 as will make the meshes of the net about three-fourths ofan inch square. 



* Had these worms been fed in the ordinary manner, they would have consumed 

 many more leaves in the same time ; but in order to preserve the greatest possible 

 accuracy, through the whole experiment, they were fed rather sparingly. 



