i) 
ri 
¥, THE 
MONTHLY MAGAZINE 


-No, xxxvil. | 


— 

For OCTOBER, 1798. 

[Vo ia 

The Numbers of this Work whichawere cut of print being now reprinted, complete Sets, in Five 
Volumes, or eny Jingle Number or Volume, may be had of any Bookjeller in the Britifh Do= 
M2iTIONS » 
‘ 
« Communications on any Subje& of a praffical or ufeful Nature, or relative to any Matters of Fag, 
“are alqays thankfully received, and joould be addreffed, pof-paid, to Mr._PuirLirs, No. 715 
St. Pauls Church Yard, London. 

To the Editor of the Monthly Magazine. 
SIR, 
AVING juit received your Maga- 
zine for March 1798, in which I 
find you have been fo obliging as, to in- 
fert the fketch I fent you of fome of my 
arguments in defence of the exploded doc- 
trine of phlogifion, and againit the uni- 
verfally prevalent one of ‘the decomprfition 
of water, I hope you will not object to 
a few more articles of the fame kind, in 
which [I fhall endeavour to be as concile 
as I poflibly can. Mares 
“If it be the water that 1s decompofed 
in procuring fixed and inflammable air 
from charcoal, by means of fteam, and 
it water confifts of oxygen and hydrogen, 
in the proportion of 85 parts of the former 
to 15 of the latter, they muft be found in 
the fame proportion in the refult of the 
experiment. Again, fixed air is faid to 
confift of 28 parts of charcoal and 72 of 
oxygen, and the inflammable air that is 
procured in this proce(fs, is faid to con- 
fift of hydrogen and a little of the char- 
coal, without any oxygen. 
But I have fhewn, that by a flow fup- 
ply of water, tlie whole of any quantity 
of it is expended without producing any 
fixed air at all; the whole produce’ being 
that kind of inflammable air which is 
faid to contain no oxygen. Confequent- 
ly, according to this experiment, there 
isno oxygen at all in water. It confifts 
of hydrogen only. 
In the fecond voltime of the new edi- 
tion of my ‘** Obfervations on Air,” 
(p. 284.) I obferve, that ‘‘ when I had 
no more water than was fufficient for the 
produétion of the air, there was never any 
jenfible quantity of uncombined fixed air 
mixed with the inflammable -air from the 
‘charcoal. This was particularly the cafe 
when I produced air by means of a burn- 
ing lens in an exhavffted receiver, or in an 
earthen retort, with the application of 
an inténfe heat. 
This is not my affertion only. ,It is 
MONTHLY Maa, No. Xxxvil. 
ORIGINAL COMMUNICATIONS. 


confirmed by Mr. Watts, whofe .ac- 
curacy no perfon will call in queftion. 
<¢ It has been ebferved,”’ he fays, © by 
Dr. Prieftley, and confirmed by myex- 
perience, that when much water patfled 
in the form of fteam, there is much fixed. 
air formed; but little or none when the 
water is admitted fo fparingly that no 
fteam reaches the refrigeratory.’’ See his 
Defiription of a Pneumatical Apparatus; 
fubjoined to Dr. Beddoes’s ** Con/idera- 
tions on the Medicinal Ufe of Fadtitious 
AYES) Der Bdoc Fie 
When I made. the experiment here re- 
ferred to, I fuppofed that heavy infam= 
mable air contained fixed air in a com- 
bined ftate, becaufe fixed air is found 
when it is decompofed with pure air. 
But I am now fatished that thisfixed air 
is produced in the procefs, by the union 
of the two kinds of air. That this mut 
be fo in fome cafes, is evident, becaute 
the fixed air fo proeured is heavier than 
all the inflammable air employed. ° 
The reafon why more fixed air is pro- 
duced when the fupply of water is. -co- 
pious, is, I prefume, becaufe more water 
is neceflary to the conttitution of fixed 
than of inflammable air. 
2. From this experiment with charcoal, - 
it would appear that water confifts wholly 
of hydrogen; but from another that I 
made with terra ponderofa aérata, it will 
appear to-confift wholly of oxygem. For 
when water in the form of fteam is made 
to pafs over this {ubftance in a red heat, 
nothing but the pureft fixed air is pro- 
cured, without any inflammable air at all. 
« Thefe experiments favour my general 
hypothefis, that water is the bafis of all 
kinds of air, and that without it no kind 
of air can be procured. In fome cafes, 
as perhaps the light inflammable air, it 
may conititute all that can be afcertained 
by gravity. And notwithftanding the 
great ufe that the French chemifts make 
of {cales and weights, they do not pre- 
tend to weigh either their calorique, or 
2 H light ; 
5 ee Se SS EEE SS Se 
