422 Dr. Wallace on the Ouk-feeding 
picul (60 kilogrammes).* As the piastre = 6 francs, these raw silks 
fetched at the place of production 55 francs the kilogramme.t At 
the same time and place were sold bales of ordinary silk, at 600 to 
612 piastres per picul, or 60 to 61 franes per kilogramme, about 
25s. per |b. 
Another and higher value was given to the silk by Mons. Pompe 
van Meedervoort,* when he brought over the first batch of eggs to 
Europe. “The silk of the Yamamaz is much esteemed in Japan, 
and is used in the Japanese crapes (so rare in Europe) to make the 
white parts. The price of the silk in Japan is 800 to 900 Mexi- 
can dollars per picul, which is nearly 4,500 to 5,000 franes, or 
133l.; or 75 to 85 franes the kilogramme, 33s. to 38s. per lb.” § 
Mons. Personnat has drawn out a calculation of the profits to be 
obtained by the cultivation on an extended scale of this valuable 
worm; though as yet few cocoons by comparison have been pro- 
duced, insufficient to enable a precise estimate of their value to 
be formed, yet the experiences of the last three years have enabled 
him to arrive at an approximate estimate of the result of culti- 
vation. || 
Suppose a hectareY] entirely planted out with oak trees: to each 
square metre might be allotted twenty to twenty-five worms; 
the amount of foliage would, we think, suffice for this. Taking 
however ten cocoons only, to allow for waste from various causes, 
as the product of each square metre, that would give 100,000 co- 
coons to the hectare; as a cocoon weighs 5—8 grammes, say 5 
grammes, 200 would weigh a kilogramme, leaving a total of 500 
kilogrammes of full cocoons for the hectare. But a deduction 
must be made for the paths, &c., say one-third, or even two-fifths, 
then that would leave 300 kilogrammes of cocoons. Now, it takes 
12 kilogrammes of cocoons to realize 1 kilogramme of raw silk, 
the value of which at Japan is 75 to 83 franes. Hence the same 
weight of cocoons would be worth one-twelfth, say 5—7 francs, 
Looking at it in another way, this silk and these cocoons have 
equal value with mulberry silk cocoons, the value of which in 
France is from 5—8 francs the kilogramme. But taking the 
* The kilogramme weighs 2 lbs. 30z. 5 dms. avoirdupois. 
+ About 23s. per Ib. 
t Vide Le Ver a Soie du Chéne, par Mons. Camille Personnat, p. 89. 
§ Since that time the price of silk has greatly risen, and is still rising. 
|| Vide Mons. Personnat’s book, p. 91. j 
{1 Nearly 2} acres, 10,000 square metres, a metre being 40 inches nearly. 
