270 
THE ART OF REARING 
portions in the heterogeneous substances varying 
the chemical action does not produce the white 
saline compound which reduces the worm to the 
mere mummy state, in which case the cocoon is 
not injured materially. This alteration is ordina- 
rily called the Blacks, (or Negrone.) 
There is another disease also called the dark 
blacks, (or Negrone,) which is produced by ano- 
ther decomposition of the worm. The heteroge- 
neous masses acting on each other, transform the 
animal substance into a soft compound, resembling 
soap, and emitting an offensive smell. If the co- 
coons that contain worms thus affected are quickly 
spun off, they may be tolerably good, but if de- 
layed, the heat of the weather will engender from 
this soapy saline matter a number of bristly and 
disgusting insects, which pierce and spoil the co- 
coon, and shortlv cast their skins and die. 
I must here observe, that there are almost al- 
ways some cocoons that have healthy and perfect 
chrysalides, mixed with those that are corrupt and 
affected, and that often on the wicker tables may 
some worms be found which are attacked by segno 
or scarlet, or by calcination (calcinaccio), when 
the greatest proportion and number of the in- 
sects are strong and well. 
The cocoons of which the worm is calcined, as 
well as those attacked by blacks, (or negrone) weigh 
perceptibly less than those containing the healthy 
