THE | ee Tae : 
MONTHLY MAGA 
No. 185. ] 
— 
JUNE 1, 
1809. [5 of Vox. 97. 
86 As long as thofe who write are ambitious of making Converts, and of giving to their Opinions a Maximum of 
* Influence and.Celebrity, the moft extenfiyely circulated Mifcellany will repay with the greatet Effect the 
** Curiofity of thofe who read either for Amufement or Ihftruction.” JOHNSON, 
ORIGINAL COMMUNICATIONS. 
To the Editor of the Monthly Magazine. 
SIR, 
N No. 183 of your very useful 
miscellany, there are some obser- 
vations respecting the formation of flints, 
from which your Correspondent | con- 
cludes, that these substances are merely 
a modification of calcareous earth. This 
theory, however plausible it may appear, 
is not new; for, in my remarks “ on the 
Identity of Silex and Oxygen,” published 
in the Philosophical Magazine for March, 
April, May, and duly, 1808,, | here al- 
luded to it, and offered some reasons for 
Opposing it, considering the doctrine as 
totally inadmissible. At present [ do 
not recollect precisely where I had read 
it, there being more than one authority 
in. which similar observations are to -ba 
found; but the first who noticed this: 
supposed transmutation was, I think, 
M. Girod-Chantrahs, whose ideas on 
this subject are detailed.in one of the 
numbers of the * Journal des Mines.” 
~The compound nature of every species 
of calcareous earth, particularly of com- 
mon chalk, in which flints most abound, 
is an insuperable objection to this opinion, 
Siliceous earth is comparatively one of 
the most simple of terrestrial substances ; 
and hence it seems absurd to suppose 
Such a mixture as chalk, or carbonate of 
lime, should so readily lose all the cha- 
racters of its respective ingredients, and 
that the lime, carbonic acid, water, iron, 
and siJex in the state of fine sand, should 
all concur to form such a simple, pri- 
mitive, and indecomposable matter as 
dint. 
Not only lime, but the whole list of 
the earths, differ so manifestly. in their 
nature and properties from, silex, that it 
seems preposterous to associate them as 
one class.” The earths possess the pow- 
ers of alkaline bodies; they neutralize 
acids, form peculiar salts with each spe- 
cies, and have all that distinctly marked 
attraction for acids asthe alkalies them- 
selves. 
Silex, on the contrary, has not only no 
such character, but in all its combina- 
. Menrucy Mac. Nov 485. ' 
S 
tions it acts rather the 
prefers. evidently an alk 
metal, to any acid whatever; 
complete combinations inhatur 
in which this element predominate 
in precious stones, and in num 
mineral productions, as. well as in glass, 
porcelain, and other such articles, the 
alkalies, earths, and metals are effectu= 
ally neutralized: the most caustic are 
rendered tasteless, the most opaque be- 
come transparent, and the most. poiso- 
nous mineral may be subdued into pete 
fect inertness, by this singular and most. 
universal of ail bodies in nature. 
Tam aware. of the objection respect= 
ing that solitary case of flworie acid; but 
having seen no such salt as the fuate of 
silex, or any combination of the kind that 
did not contain other matters, or that 
had not some palpable defect; I shall, foi 
the present at least, pass the question. 
The circular cr nodalar figure of flints 
that are found in chalky does not demon- 
Strate a progressive accumiulation; this 
circumstance is rather a decided mark of 
solution or abrasion, This may be 
t ofan acid ; it 
1 earth, ora 
readily illustrated by familiar examples, ue 
such as pieces of wax or metals while 
melting, the solution of earths, stones, 
or metals in acids, oreven that of a piece 
of crystallized sugar in water; for, in all 
these instances, the projecting or angue 
lar parts are the first that yield to the 
solvent. ; 
There is no necessity to pursre this 
subject farther, as, in the remarks which 
i have quoted, it may be seen, that I 
have already espoused the converse of 
this question, being rather inclined to’ 
conclude, that lime derives its existence 
from silex: for, besides the pieces of 
flint that are obvious, and often in strata, 
there is not an atom of the purest chalk 
that is free from sand, or most minutely 
divided silex: and this, with other core 
roborating circumstances, has. contri« 
buted to lead my opinion. i 
Controversies of this kind cannot, howe 
‘ever, be very lasting, since so much has 
lately been accomplisked through the 
3K ‘wonderfid 
ZINE. 
