352 Action of Coloured Light on Carp. [June, 
Feb . 10th . — ' They were considered by four persons, making 
independent observations, to be darker than the normally 
coloured fish. 
The carp in the blue globes became of a beautiful purplish 
velvety darkness, deepest on the back : their fins changed to 
bright red, and their whole appearance became vigorous and 
handsome in the extreme. 
In the red and yellow globes the fins of the carp continued 
much the same shade of colour as their bodies, while the 
whole appearance of the fish was less vigorous than that of 
those kept in the blue globes. 
Unfortunately, these fishes were attacked by a parasitic 
growth, and it was then observed that those carp which dwelt 
in the blue globes made by far the strongest resistance to the 
attack of disease, and did not succumb until the parasite had 
attained double or treble the size which caused death in the 
other carp. 
Second Series. 
Commenced April *]th, 1882.— Experiments were started on 
red, yellow, blue, green, and black, and also a standard of 
comparison in clear white glass. 
Three experiments for each colour in three separate globes. 
On the 14th of April they were examined, when a great 
change had taken place. The blue were found to be by far 
the darkest, to have bright red fins, and looked the most 
healthy. Next to the blue the black came in darkness of tint, 
and with fins slightly tinged with red, but were not so healthy 
looking. The fish in the green glass globe came next in 
order of darkness, while those in the red glass remained un- 
changed ; but the fish in the yellow glass were much lighter 
than the standard of comparison. 
The green were by far the most languid and unhealthy. 
On the 21st all these fish were again observed, with the 
same result as on the 14th. 
It will be seen that the second series of experiments fully 
bears out the first in demonstrating that colour is an 
essential fadtor in the health and appearance of fish. 
These experiments are being prosecuted further. 
