278 
NATURAL HISTORY. 
“ To the artificial manures we have here enumerated, we could add 
some few others which are nearly equal in importance, and a great 
variety which are commonly applied as top-dressings to land, to 
make up for a deficiency in the staple manuring at the period of 
sowing. Some of these are very good for this purpose, though they 
are seldom relied on, but in conjunction with other matters previ¬ 
ously laid on, and all that are efficacious are sold at a high price. 
The cost will, in most instances, be found to be in proportion to 
their usefulness. A sufficient quantity to put an acre of land in good 
heart cannot be obtained for less than from fifty to sixty shillings. 
Mark the difference in the expense of decomposed salt. For ten or 
twelve shillings we get enough of this material to do the work of any 
other that costs four or five times as much. A ton is sufficient for 
three acres. Think then of the facility of transporting such a means 
of fertility throughout the country. The great arteries for inland 
conveyance, rivers, canals, and rail-roads, offer the ready means of 
sending it to so many points, that a supply may, with ease, be ob¬ 
tained for every acre in the kingdom. Of all the manures, it may 
be said, that they are totally inadequate to the wants of the earth. 
In all probability, if the whole consumption of artificial manures in 
the country were concentrated on a single county, (say Yorkshire,) 
it would be sufficient so to satisfy its demands as to produce all the 
fertility of which it is capable. Now we have the satisfaction of 
knowing, that the sources of salt are absolutely boundless, not only 
for the supplying a kingdom, but for the wants of a world. The 
supply from mines and the ocean may well be considered infinite.” 
NATURAL HISTORY. 
ARTICLE XVII. 
THE PRESENT EXISTENCE OF MAMMOTHS, AND OF OTHER ANIMALS 
Found contemporaneously with them, in a fossile state, 
DISPUTED BY “a TRUTH LOVER.” 
In page, 141, I observed an extract, taken from the Field Naturalist’s 
Magazine, in which it is stated as possible that the Icthyosaurus, 
Plesiosaurus, and the animals found contemporaneously with them in 
a fossil state, generally supposed to be extinct, may at present exist 
in dense (proves, mountains, valleys, &c. two or three miles under the 
surface of the sea. The whole extract appears to me to abound with 
