ount of the days since we were cast upon our island, in
order that we might remember the Sabbath-day, which day we had hitherto
with one accord kept as a day of rest, and refrained from all work
whatsoever. However, on considering the subject, we all three
entertained the same opinion as to how long we had slept, and so our
minds were put at ease.

We now hastened to our Water Garden to enjoy a bathe, and to see how did
the animals which I had placed in the tank. We found the garden more
charming, pelucid, and inviting than ever, and Jack and I plunged into
its depth, and gambolled among its radiant coral groves; while Peterkin
wallowed at the surface, and tried occasionally to kick us as we passed
below. Having dressed, I then hastened to the tank; but what was my
surprise and grief to find nearly all the animals dead, and the water in
a putrid condition! I was greatly distressed at this, and wondered what
could be the cause of it.

"Why, you precious humbug," said Peterkin, coming up to me, "how could
you expect it to be otherwise? When fishes are accustomed to live in the
Pacific Ocean, how can you expect them to exist in a hole like that?"

"Indeed, Peterkin," I replied, "there seems to be truth in what you say.
Nevertheless, now I think of it, there must be some error in your
reasoning; for, if I put in but a few very small animals, they will bear
the same proportion to this pond that the millions of fish bear to the
ocean."

"I say, Jack," cried Peterkin, waving his hand, "come here, like a good
fellow. Ralph is actually talking philosophy. Do come to our
assistance, for he's out o' sight beyond me already!"

"What's the matter?" inquired Jack, coming up, while he endeavoured to
scrub his long hair dry with a towel of cocoa-nut cloth.

I repeated my thoughts to Jack, who, I was happy to find, quite agreed
with me. "Your best plan," he said, "will be to put very few animals at
first into your tank, and add more as you find it will bear them. And
look here," he added, pointing to the sides of the tank, which, for the
space of two inches above the water-level, were incrusted with salt, "you
must carry your philosophy a little farther, Ralph. That water has
evaporated so much that it is too salt for anything to live in. You will
require to add _fresh_ water now and then, in order to keep it at the
same degree of saltness as the sea."

"Very true, Jack, that never struck me before," said I.

"And, n