32 UTILIZATION OP MINUTE LIFE. 



of the grub, and coloured the cocoon mechanically 

 during its construction. This appears to be the reason 

 why the coloured silk that was obtained in these ex- 

 periments was neither uniform in tint nor of a good 

 colour. Others, however, still persist in a contrary 

 opinion. M. Roulin commenced his experiments by 

 sprinkling indigo over the mulberry-leaves, and 

 obtained blue cocoons ; he then experimented with 

 chica, a fine red dye extracted from the Bignonia 

 chica, which the Indians of Oronoco employ to dye 

 their skin, and obtained cocoons of a red colour, 

 with a tolerably uniform tint, and of a permanent 

 dye. He still continues these investigations, 

 hoping to obtain silk ready dyed of all kinds 

 of colours. 



Whatever may be thought of these experiments 

 as they now stand, they are novel, and should there- 

 fore be encouraged. It would, probably, be worth 

 while to try the effect of the famous new green 

 dye, Lo-ltao, mixed with the diet of the silkworm. 

 This colour, which is one of the most beautiful and 

 most extraordinary dyes ever yet produced, has 

 great affinity for silk ; it is extracted from several 

 species of Rhamnus, and we have seen that certain 

 varieties of silkworm feed upon the leaves of plants 

 (Zizyphus, etc.) of the same family. 



Kirby and Spence have informed us that Don 

 Louis Nee observed on Psidium pomiferum and P. 



