1884. 
The Health Exhibition. 
579 
species resemble each other closely in their colouration, 
though the adults are quite distinct. 
Whilst thus giving an abstract of the very interesting 
results of Signor Lorenzo Camerano, we are fully con- 
scious that some of them — as we have pointed out — 
require further consideration. It must have struck many 
of our readers that researches on the colouration of 
animals have, so far, left the physical side of the 
question scarcely touched. The production of the colouring- 
matters, their occurrence in one species and not in another, 
and the mechanism of their distribution have still to be 
dealt with. It strikes us that in the production of the 
design— in, e.g., the wings of a butterfly— the principles of 
capillary attraction and of diffusion must come into play. 
By mixing certain colours which have different rates of 
diffusion, and placing a small drop of the mixture on white 
blotting-paper, designs may sometimes be obtained which 
roughly resemble those we meet with in the wings of 
Lepidoptera. 
III. THE HEALTH EXHIBITION. 
No. III. 
t~V/Q 
,NCE more we return to this popular display to notice 
a few points which we had previously overlooked. 
Disinfectants are, as a matter of course, not absent. 
As sings the poet Buchanan : — 
“ Down the steep valley, on her ass 
Rideth the maiden Sanitas.” 
Messrs. Savory and Moore have a fine collection of the 
leading antiseptics of the day, — salicylic acid, phenol, euca- 
lyptol, thymol, &c. The phenol (pure) is very slightly tinted 
with pink, the inevitable result of exposure to light. All 
these specimens are exceedingly beautiful. 
“ Ozonine ” deceived us : we expected that it was some 
novel antiseptic ; but behold, it is a beverage, to be consumed 
instead of champagne. 
We were particularly struck with the exhibits of the 
