SILK-WORMS. 
269 
If the saline particles which envelop the 
worm or chrysalis can have formed without much 
moisture, or if the moisture of it have quickly 
evaporated through the cocoon, the worm will 
not have spoilt the cocoon, which may be pre- 
served in perfection for a long period. If, on the 
contrary, these saline particles have retained their 
moisture, or if much moisture has exuded from 
the mummy of the silk-worm, and the moisture 
mixed with the saline substance has remained in 
contact with the inside of the cocoon, it will soil 
and stain it, which renders it less proper for spin- 
ning, and diminishes its value. In both cases the 
silk-worm is covered with the white saline en- 
velope. 
It however happens sometimes, that the pro- 
is peculiar to tlie healthy chrysalis. It would appear, there- 
fore, that this acid has not been formed, or that it has under- 
gone decomposition, by action of the superior attractions and 
chemical affinities of the other substances, which afterwards 
in combination, have formed the saline compound above 
stated, called by chemists, ammoniaco-magnesian phosphate. 
This great change in the silk-worm, demonstrating that by 
ill-management there has accumulated within it a large 
quantity of heterogeneous matter, against which it has strug- 
gled until the end of the fifth age, or beginning of the sixth, 
presents a strong idea of its prodigious strength of organiza- 
tion ; it not only has resisted so great an alteration, but pre- 
served the faculty of pouring the silk it contained, before the 
chemical affinities could act upon its frame to destroy it, and 
form a new compound of a substance entirely different from 
the animal substance. 
