355 
•of an important constituent, they might have sooner applied the remedy, 
and prevented the loss consequent on the diminished produce of their 
pastures. So with the farmer in the green sand district; if lie had pre¬ 
viously known that some of his land was already rich in phosphates, he 
would have saved the money, time, and material expended in applying 
bones to a soil in which they were not wanted. Sir John Johnstone, 
whose remarks on the geological sitrvey of his estate I have previously 
quoted, states, that besides obtaining clearer views of the true conditions 
of vegetable life, he derived the following positive practical results from 
the survey :—1. the knowledge of applying lime to advantage over the 
property—2. laying down fields to advantage to grass, and where and 
how to plant wheat—3. what sort of trees to plant on each stratum. 
Before taking leave of this subject we may consider for a moment 
what useful results flowed from the farmer on the green sands possessing 
an inquiring mind. He was not content to know that bones were of no 
use on some of his fields, he desired to know why they were useless, 
and he wisely applied for information to the geologist and chemist; men 
who had made the arrangement and the composition of rocks their 
especial study, and who, of all men, were best qualified to give him a 
satisfactory answer. The results obtained by the farmer through trial 
and error, and the explanation of these results afforded by the investi¬ 
gations of the geologist and chemist, became the common property of 
all the farmers located on the green sand. They were all, from that 
time, saved from making the important mistake of purchasing and 
applying a costly material to their soil in the vain hope of adding to its 
fertility ; and the knowledge thus acquired may prove useful, not only 
to the farmers of that locality, but to farmers in other parts of the 
world, wherever the green sand is known to exist. There is a great 
similarity in the same kind of rock wherever found; it is, indeed, by 
their family chiefly that many rocks are distinguished. The benefits 
resulting from this investigation did not end here ; it suggested the fur¬ 
ther inquiry, if these fossils are so rich in phosphates that they anticipate 
the action of bones on this soil, may they not prove beneficial, and be 
used as a substitute for bones on other soils requiring phosphates ? Ex¬ 
periment was again resorted to, and the question being answered in the 
affirmative, these fossils are now extensively collected, and their phos- 
