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the animals, only a small number of which therefore can be 
kept in great hulks of fluid, because it is insufficiently aerated. 
This will be the case also at the Scarborough aquarium, now 
being built on the same erroneous principle. 
Dalyell, however, was no mechanician or physicist, and he 
knew nothing of marine botany ; so he just did as his neigh- 
bours did with their fresh-water gold-fish globes — he changed 
the sea-water and threw it away as quickly as it became sullied, 
and this water he obtained at no great cost, he living close to 
the sea. Or if the cost of time in getting it was considerable 
in proportion to the work done, i.e. the quantity obtained, it 
mattered not much to him, as he was a rich man. Yet, had 
he but known it, the sea-water he thus obtained was less good 
for the animals he kept than it should have been, inasmuch 
that it was from the adjoining Firth of Forth, and of the 
density of but 1*024, at a temperature of 60° F. ; whereas had 
he kept it for some months, it would have evaporated to the 
more proper density of 1*027 at 60° F., taking distilled water as 
being 1*000 at 60° F. 
I have given this narration as showing the state of things 
aquarially at the end of the last century, and during the first 
half of the present one, and also as being the mode of operation 
which the general public, and even the great mass of the higher 
and better educated classes of society, still believe to be the 
system necessary to be followed in the maintenance of aquaria. 
In the year 1842 the late Dr. N. B. Ward published the first 
edition of his book, in 8vo., on the growth of plants in closely 
glazed cases, and this in 1854 was followed by the second 
edition, in 12mo. In 1853 Dr. N. B. Ward’s son, the present 
Dr. Stephen H. Ward, gave a lecture on this subject at the 
Boyal Institution, which was published as a 12mo. pamphlet in 
the same year. All three of these are now and have been long out 
of print, and they bear testimony, indubitably, that N. B. Ward 
experimented with aquaria about the year 1840, though he 
did not use the word “ Aquarium,” which was employed for 
the first time in print, as far as I know, twice by Mr. P. H. 
Grosse, in his “Devonshire Coast,” post 8vo., 1853, at pages 234 
and 441. That is to say, N. B. Ward is the earliest recorded 
person who intentionally arranged together certain animals 
and plants in water, so that these two sets of organisms should 
mutually and partly support each other, the plants giving 
off oxygen and taking up carbon, and the animals taking 
up oxygen and giving off carbon, thus decomposing and 
rendering harmless the carbonic acid gas as continually as it 
was evolved by the animals, and maintaining the water pure. 
In Dr. S. H. Ward’s pamphlet, just named, is a long, circum- 
stantial, and most interesting narrative of how Mrs. Anne 
