” 
so thatein every part of the globe a dou- 
bling in twenty-five years ought to take 
place. Supposing this to be accomplished, 
@ question naturally arises, how are the 
means of stibsistence to be provided? The 
increase of population is geometrical, if 
there are mulligghgipeonie to day, 
in twenty-five years there will be four, 
in twenty-five years more there will be 
eight, so that in two hundred years, two 
millions will increase to five hundred 
and sixteen. It is absolutely impossible 
that an increase in the means of subsis- 
tence should go on at the same rate, but 
lowing that by breaking up fresh land, 
nd by such an improvement in the sys- 
tem of agriculture, that even the desert 
shall be made to reward the husband- 
man, yet the periud must come, when 
the remotest corner shall be cultivated, 
and the whole produce no more than 
suflicient for the existing population. An- 
other. double, and the world is too full, 
the means of subsistence for only one 
half can be obtained, of course the other 
half must die of want. Such Mr. M. con- 
cludes is the necessary consequence of 
the natural increase of the human race: 
but this increase is checked; one person 
dies before his natural term of life, by 
war; another by famine, another by pes+ 
tilence; a fourth lives in celibacy, a fifth 
cuts his life short by excess ; and thus by 
vice, misery, and moral restraint, the po- 
pulation is kept down to the level of sub- 
sistence. Such are the, laws of nature, 
that a nation has one of two alternatives, 
either to suffer from war, pestilence, or 
famine, or for a considerable portion of 
its population to live in celibacy. I 
have here given a fair representation of a 
theory which Mr. Malthus professes, and 
which many otver philosophers believe 
to bewnanswerable. There are some, 
however, of a contrary oj isin; the fore- 
most me is. Dr. Jarrold, This gen- 
tleman, in his answer to Mr. Malthus, is 
of opinion, that Mr. M. formed a the- 
ory, and then endeavoured to bend the 
history of mankind to itssupport: in doing 
which, he says, Mr. M. brought forward 
many facts which are in direct opposition 
to it; for instance, Mr. M. hus taken the 
rate of increase in america, as the na- 
tural rate for the whole world: but unfer 
tunately for his theory, he proves as a 
leading fact, that the number of childreit 
born to a marriage, are not the same on, 
an average in any two considerable na- 
tions ; the Indians in America and else- 
‘ where, have not so many as three, while 
‘the Scotch have more than six. If the 
pe Ties 
number of children to a marriage be not 
equal, it is impossible that two nations 
should multiply at the same rate. Again, 
Mr. M. contends, that population inva- 
riably increases where the geaus of sub- 
sistence increase. iow is it then, says 
Dr. J. that some countries for ages ex- 
ported corn, and yet the population has 
remained stationary; how is it that the 
Chinese have not increased? Dr. J. 
having pursued Mr. M. step by tep, at 
length advances a theory of his | 
says, that population is not regulated by 
the quantity of corn, but by the state of 
civilwation ; no enlightened or enterpri- 
sing people has, at any time gpepilly 
increased, neither has any people sunk 
in barbarism, Freedom from care is es- 
sential to a rapid increase of population ; 
the influence of the mind upon the body, ~ 
as it respects the capacity of propaga- 
tion, is the sum of Dr. J’s. theory, which 
he exemplifies hy a variety of evidence. 
Such are the two theories,the one frowns 
in blackness, dragging vice and misery in 
its train; the other smiles upop man, aia 
bids him be happy: but which theory is 
true? The question is important to the 
politician, and the moralist. Any observa- 
tions will greatly oblige, at least a pare 
of your readers, Your's, &c. 
~ Juntus. 
For the Monthly Magazine. | 
ACCOUNT OF PROPESSOR DAVY 
GRAND GALVANIC BATTERY, 
With an Engraving. x 
HIE galvanic troughs which compose 
this battery are arranged round 
SOME 
. 
* 
+ 
a 
12 ‘" Mr. Malthus and Dr. Jarrolt, on Population. [Avg. ty # 
1 
five tables, which are too saith “4 
a 
shewn in the engraving to require any 
letters of reference; the trough @ is the ~ 
first of the positive end of the battery, 
the wire a coming from it, conveys the 
efreet of all the battery to the place 
where the experiments are made, which 
is in the clear space upon the centre 
table, the next trough is 6 connected 
with a, by means of apiece of thin sheet ~~ 
lead y; the troughs then follow round the 
tables in the order of the Tetters. of 
reference, cde fghikimno pqrst 
w, each being connected with the ad- 
jacent one by a piece ot lead y, until we 
artive at ¢ and 0, where two troughs cor~ © 
responding with @ and 6, are placed in 
the middle of the tables, the trough v is 
the first of the negative, and has a cop- 
per wire w proceeding from it, which is 
wrapped round the end of a small probe 
of platina; the positive wire 2 is con- 
nected with a small platina dish or sau- 
cer; the piece of potash which is to be 
4 decomposed, 
ge? it 7 ay , e Pia 
a % “ , a ‘a 
rs 
” 
4 
. 
** 
