Geology of Norfolk. 
453 
farmers being still blind to its merits, because it is not marl, but 
clay, by which name," he says, " it is universally known." 
"The name, however, would be of little importance, were it not indiscri- 
minately applied to unctuous earths in general, whether or not they con- 
tain any portion of calcareous matter. Nothing is marl which is not white, 
for notwithstanding that the county has been so long and so largely in- 
debted to its fertilising qualities, her husbandmen, even in this enlightened 
age, remain totally ignorant of its fertilising properties ; through which 
want of information much labour and expense are thrown away. One 
man, seeing the good effect of the Flegg clay, concludes that all clays are 
fertilising, and hnding a bed of strong brick-earth on his farm, falls to 
work at a great expense claying, while another, observing this man's mis- 
carriage, concludes that all clays are unprofitable, and in consequence is 
at a great expense, equally misapplied, in fetching marl from a great dis- 
tance, while he has perhaps, on his own farm, if judiciously sought, an 
earth of a quality equally fertilising with that which he is throwing away 
money and time in fetching. This is a strong evidence of the utility of 
chemical knowledge in the investigation of fossil manures." 
In describing the chalk marl of Thorpe Market, he notices the 
singularity of its position : — 
"It does not lie in strata, as fossils do in general, nor in a continua- 
tion of rocks like chalk and limestone, but in distinct masses of different 
figures and magnitudes, rising with irregular heads towards the surface, 
and sinking to a depth of perhaps 10 and 20 feet, and sometimes 
to a depth unfathomed. If the abyss of sand, in which they lie buried, 
could be rendered transparent, these clouds of marl would, I apprehend, 
be seen scattered under the surface of this country in resemblance of 
the clouds of vapour which we frequently see in summer suspended in 
the atmosphere." 
He then notices the variations in the composition of these 
masses, from an intermixture of other than calcareous matter, 
and adverts to the lumps of chalk and the flints which they con- 
tain, similar to those found in the chalk pits of other districts. 
We here recognise geological facts correctly observed, though 
the fathomless ocean of sand, and the clouds of marl rising like 
vapour through it, are exaggerated and fanciful descriptions, and 
savour somewhat of the cosmological speculations of the day. 
At a later period, in his ' Agriculture of the Southern Coun- 
ties,' published in 1797, we find Marshall using the word geology,* 
* Having but little acquaintance with the obsolete literature of geology, 
I supposed this to be the first instance of the use of the term. With the 
Wernerians the science was " geognosy," with Smith " mineralogy," and 
he styled himself a " mineral surveyor." On referring the question to 
those geologists the most likely to possess information on this point, I 
found them unable to call to mind an instance of the use of the word in 
any treatise older than 1799. The earliest period to which I have suc- 
ceeded in tracing it is 1755. In the first edition of ' Johnson's Dictionary' 
of that year, geology is defined to be " the doctrine of. the earth," without 
