51% 
and calls it the ponderable bafis of oxy- 
gene gas. Dr. Gibbes conceives himlelf 
warranted by experiment to fay that oxy- 
gene gas is produced by the union of po- 
fitive ele&tricity with water ; hydrogene 
gas by the union of negative electricity 
with water ; and that water uniting in 
different proportions with the two ele¢tri- 
cities is the ponderable part of the elaftic 
fluids. Itis evident that the wire from 
the Galvanic pile or trough, which is 
found to be pofitively electrified, produces 
oxygene gas when immerfed in water.— 
The negative wire in fimilar circumftances 
produces hydrogene gas. By the pofitive 
ele&iricity metals are oxidated: blue vege- 
table colours are reddened. The acidifying 
effeét of electric comniotions in the atmo- 
fphere on weak termented iiquors is well 
known. By the negative eleétricity the 
vegetable blue is reftored ; the oxydated 
metal revived. 
Thefe circumflances, amongft others, 
lead Dr. Gibbes to conclude, that when 
hydrogene gas is produced by the affufion 
of water on red-hot metal, and the metal 
is at the fame time oxydated, a decompe- 
fition of fire, rather than of water, has 
taken place: that the hot metal has part- 
ed with negative eleétricity, which, unit- 
ing with a {mail proportion of the water, 
has formed hydrogene gas: that a greater 
proportion of water has united with the 
pofitive eleftricity, and entered as oxy- 
gene 92s into combination with the me- 
tal. When the two gaffes are inflamed 
together, the fpark attraéts to itfelf, in 
due proportions, the two eleétricities con- 
tained in the two gafics, which unte with 
explofion, and produce fire. The water 
with which taey were before combined is 
of courfe depofited. 
It is well known that each of the elec- 
tricities repels its like : each atiraéts its 
oppofite. The two ejefiricities are found 
to refide in almoft al] fubitances ;. perhaps 
blended in different proportions in al] fo- 
lids and liquids. 
ble, that in the two uniferm fluids the 
éle&tricities are almoft, or entirely, dif- 
ting. Inflammable fubftances burn in 
oxygene gas, notin hydrogene gas: (at 
Jeaft, not in the latter, except under very 
peculiar circumflances. In Accum’s Che- 
mittry, @n experiment is mentioned, in 
which a mixture of fulphur and copper 
filing was inflamed both in hydrogene gas 
and in carbonic acid gas). But the rea- 
fon why, generally fpeaking, combuftion 
may be effected in the former, and not in 
the latter, is, no doubt, owing to the 
prevalence of negative electricity in all 
Defiription of a Perpetual Sea-Log. 
It is, however, proba-. 
[July 1, 
inflammable fubftances. Thus when a 
red hot metal is oxydated by affufion of 
water, the quantity of hydrogene gas is 
enormoufly difproportionate io that of 
oxygene gas which may be forced from 
the oxyde. Neither of the gaffes ean be 
inflamed feparately, becaufe fire depends 
on the union of the two eleftricities ; and 
fuch union cannot be effected unlefs both 
are prefent in due proportion. 
The feparate eleftricities appear to have 
fome properties which they no longer pof- 
fels in their united ftate. They confti- 
tute the permanent elafticity of the 2éri- 
form fluids, which are incompreffible by 
cold, probably bya more: perfeé& union 
with water, than takes place between fire 
and water, when expanded as a liquid, or 
in the form of vapour. 
I fhall no farther anticipate Dr.Gibbes’s 
developement of his theory, which he will 
no coubt illuftrate by adue detail of expe- 
riments, fhewing, in regard to the princt- 
pal phenomena of chemittry, that we have 
abundant evidence of the agency of the 
two eleétricities in the produétion of re= 
fults attributed to the operation of the 
hypothetical oxygene and hydrogene; 
and that the aétion of the former is diftin- 
guifhable in, and affords an eafy folution 
of certain phenomena, which the Lavoi- 
ferian principles can in no way be applied 
toexplain. Iam, Sir, your’s, &c. 
ZETETES. 
= 
For the Monthly Magazine. 
DESCRIPTION of @ PERPETUAL. SEA= 
LOG, tmuented by MR. GOULD, aK 
AMERICAN. 
N inftrument, whereby the velocity 
of a fhip going through the water 
can be afcertained- with precifion, is a 
grand defideratum in nautical affairs —= 
By the affiftance of fuch an inftrument, 
compared with folar and lunar obferva- 
tions, the exact {pot of the globe which a 
fhip occupies may be reduced to a cer= 
tainty. ‘he common log is acknowledg- 
ed to be very defective, and inadequate to 
the purpofe. This invention feems to bid 
fair to give birth to a fcheme which will 
rectify all its errors (except with refpect 
to currents, the effects of which will, how= 
ever, be confiderably diminifhed) ; fuch as 
the badnefs of the minute, or half-minute 
giafs; the uncertain length of the log- 
line, which fometimes ftretches confider~ 
ably; the unfkilfulnefs of the experi- 
menter; and the variable ftate of the wind, 
heave of the fea, &c. ies 
The new-invented machine is towed | 
¢ 1) er 
