Tue Zoo.tocist—Auecust, 1876. 5037 
He then proceeds to give some interesting details :— 
“ Yet in this comparatively small quantity (120,000 gallons) of unchanged 
fluid we have, from September, 1871, to March 31, 1876 (four and a half 
years), given to the animals in it the following enormous quantity of food 
without the water being otherwise than always sparklingly clear :— 
1. Sandhoppers (Talitrus), in pounds weight - : : 12 
2. Shrimps (Crangon) in quarts - - - - 4735 
3. Crabs (Carcinus) in gallons - - a beers 
» (Cancer), large », numbers : - - 1450 
4. Scallops (Pecten), large, in numbers - - - 32 
5. Oysters (Ostrea) r . - - - 2195 
6. Cockles (Cardium), in gallons : - : - 18 
7. Mussels (Mytilus) = - : - - 3544 
._, ¢ in gallons - : : : t 
8. Whelks (Buceinum) { Pe ubest : : og 
9. Fish, chiefly whiting (Gadus), in pounds weight - - 3159 
10. Smelts’ roe (Osmerus) " hi : : 14 
11. Green seaweed (Ulva), purchased x - - 400 
ee »  (Conferva), grown in tanks, quantity unknown. 
And, in addition, we obtain occasional and unrecorded supplies from neigh- 
bouring fishmongers when the regular supply runs short. Of this animal 
food, all but the denominations 9 and 10 are kept alive in a series of reserve 
tanks till the moment of being eaten. Scarcely any uneaten food, and 
never any excrement, is manually removed; but all which is not consumed 
by the animals is chemically dissipated, without filtering, by the enormous 
volumes of air constantly being injected into every tank by machinery, the 
speed of which is accelerated (i. e., the oxygenation is quickened) when the 
water is slightly turbid from an excess of organic matter. All this I have 
explained more at length in the ‘ Official Handbook to the Crystal Palace 
Aquarium,’ and in ‘ Observations on Public Aquaria,’ both published at the 
Crystal Palace. It is this power of oxygenating, or consuming, or burning, 
at a low temperature, termed by Baron Liebig ‘eremacausis,’* which 
expresses the real work done in an aquarium, and the force necessary to do 
that work.” 
oo 32 He * * % 
“Of the general influence of aquaria on Zoology we have curious 
evidence in Mr. Gosse’s most excellent ‘Manual of Marine Zoology for the 
British Isles,’ published in two volumes, in 1855—1856, in which the 
author cnumerates 1785 species, from sponges to fishes, and of which he 
* From the Greek “to remove by burning, or by fire.” The words “ caustic” and 
“ cautery” haye the same derivation. 
SECOND SERIES—VOL. XI. 2K 
