CHAMELEON. 
59 
that only the first time the experiment was made, 
though it was repeated several times on different 
days. 
cc In making these experiments, we observed that 
there were a great many places of its skin which 
grew brown, but very little at a time : to be certain 
of which, we marked with small specks of ink those 
granules which to us appeared whitest in its pale 
state ; and we always found that when it grew 
brownest, and its skin spotted, those grains which 
we had marked were always less brown than the 
rest.” 
M. d’Obsonville thinks it probable that the 
change of colour in the chameleon depends upon 
a mixture of blue and yellow, from which result 
the different shades of green : this opinion of his is 
founded on the appearance of the blood, and of the 
vessels which contain it. He tells us that the 
former is of a violet blue, and will preserve its co- 
lour for some minutes on linen or paper, if it has 
been previously steeped in a solution of alum ; that 
the coats of the latter are yellow, as well in their 
trunks as their branches, and that consequently the 
mixture of the two will produce a green. But he 
proceeds further, and calls to his aid the passions 
of the animal to account for the different shades of 
this colour. Thus, when a healthy chameleon is 
provoked, the circulation is increased, and, being 
carried with violence from the heart to the extreme 
parts of the body, distends the vessels that are 
spread over the skin, and produces a superficial 
