5 r A 
R E P 
REP 
R E Q 
t; on of cohesion may bo substituted for it 
with success. A large lump of charcoal, for 
instance, will not unite with oxygen at so Iowa 
temperature as the same charcoal will do when 
re. Inced to a very fine powder ; and charcoal 
will combine with oxygen at a still lower 
temperature, if it is reduced to its integrant 
particles, by precipitating it from alcohol, as 
Dr. Prisstley did by passing the alcohol 
. through red-hot copper. And to shew that 
there is nothing in the nature of oxygen and 
carbon which renders a high temperature 
Accessary for their union, if they are present- 
ed to each other in 'different circumstances, 
they combine at the common temperature of 
the atmosphere ; for if nitric acid, at the 
temperature of 6°, is poured upon charcoal- 
powder, well dried in a close crucible, the 
charcoal takes fire, owing to its combining 
v, ith the oxygen of the acid. And in some 
other situations, carbon is so completely di- 
vided that it is capable of combining with the 
oxygen of the atmosphere, or, which is the 
same thing, of catching fire at the common 
temperature: this seems to be the case with 
it in those p rophori that are formed by dis- 
tilling to dryness several of the neutral salts 
which contain acetous acid. These observa- 
tions are sufficient to shew, that caloric is in 
many cases necessary in order to diminish 
the attraction of cohesion. 
But there is a difficulty still remaining. 
How comes it that certain bodies will com- 
bine with oxygen without the assistance of 
posed, because its light is dissipated, but be- 
cause the coal cannot be converted into va- 
pour by the degree of heat which it contains, 
and because the cohesion of its particles is 
too great to allow it to combine with oxygen 
without some such change. r l here are some 
coais, however, which contain such a quan- 
tity of bitumen, that they will burn even in 
the situation supposed bv Dr. Hutton, and 
continue to burn, provided they are furnished 
with any tiling to act as a wick. It is need- 
less to add, that bitumen, like oil, is easily 
converted into vapour. 
But this explanation, instead of removing 
our difficulties, has only served to increase 
them : for if caloric only acts by diminishing 
the attraction of cohesion, and converting 
these substances into vapour, why do not all 
elastic fluids combine at once without any ad- 
ditional caloric? why do not oxygen and hy- 
drogen, when mixed together in the state of 
gas, unite at once and form water? and why 
do not oxygen and azote, which are constantly 
in contact in the atmosphere, unite also and 
form nitrous gas? Surely it cannot be the 
attraction of cohesion that prevents this 
union. And if it is ascribed to their being 
already combined with caloric, how comes it 
that an additional dose of one of the ingredi- 
ents of a compound decomposes it ? Surely, 
as Mr. Monge has observed, this is contrary 
to ail the other operations in chemistry. 
That the particles of fluids are not desti- 
tute of an attraction for each other, is evident 
any foreign heat, provided the combination is : rom numb ei less facts. 1 he particles of wa- 
once begun, though a quantity of caloric is 
necessary to begin the combination ; and that 
other bodies require to be surrounded by a 
great quantity of caloric during the whole 
time of their combining with oxygen? Alco- 
hol, for instance, if once kindled, burns till it is 
quite consumed; and this is the case with 
oils also, provided they are furnished with a 
wick. 
We should err very much, were we to sup- 
pose that a high temperature is not as neces- 
ter draw one another after them in cases of 
capillary attraction; which is probably owing 
to the attraction of cohesion. It is owing to 
the attraction of cohesion, too, that small 
quantities of water form themselves into 
spheres; nor is this attraction so weak as not 
to be perceptible. If a small plate of glass is 
laid upon a globule of mercury, the globule, 
notwithstanding the pressure, continues to 
preserve its round figure. If the plate is gra- 
dually charged with weights one after an- 
sary to these substances during the whole of other, the mercury becomes thinner and thin 
their combustion as at the commencement of > ner, and extends itself in the form of a plate ; 
it: for Mr. Monge found, on making the ! but as soon as the weights are removed, it 
trial, that a candle would not bum after the 
temperature of the air around it was reduced 
below a certain point. 
All substances which continue to burn after 
recovers its globular figure again, and pushes 
up the glass before it. Here we see the at- 
traction of cohesion, not only superior to gra- 
vitation, but actually overcoming an external 
being once kindled are volatile, and they i force. And if the workman, after charging 
burn the easier in nronortion to that volati- ! his plate of glass with weights, when he is 
forming mirrors, happens to remove these 
burn the easier in proportion to that volati- 
lity. The application of a certain quantity 
of caloric to alcohol volatilizes part of it, that 
is, diminishes the attraction of its cohesion, so 
much that it combines with oxygen. r Ihe 
oxygen which enters into this combination 
gives out as much heat as volatilizes another 
portion of the alcohol, which combines with 
oxygen in its turn, more heat is given out; 
and thus the process goes on. Oils and tal- 
weights, the mercury which had been forced 
from under the glass, and was going to sepa- 
rate, is drawn back to its place, and the glass 
again pushed up. Nor is the attraction of 
cohesion confined to solids and liquids; it 
cannot be doubted, that it exists also in gases; 
at least it is evident, that there subsists an 
attraction between gases of a different kind ; 
low exhibit the very same phenomena; only for although oxygen and azotic gas aie ot dit- 
as they are less volatile, it is necessary to ! ferent gravities, and ought therefoie to occu- 
assist the process by means ot the capillary j py different parts of the atmosphere, we find 
attraction of the wick, which confines the ac- 1 them always mixed together ; and this can 
only be ascribed to an attraction. 
It seems evident, in the first place, that 
the affinity between the bases of the gases 
under consideration and oxygen, is greater 
than their affinity for that dose of caloric 
which produces their elastic form; for when 
they are combined with oxygen, the same 
dose will not separate them again. Let us 
take hydrogen for an instance. The affinity 
tion of the caloric evolved to a small quan- 
tity of oil, and thus enables it to produce the 
proper effect. In short, then, every sub- 
stance which is capable of continuing to burn 
after being once kindied is volatile, or capable 
of being converted into vapour by the de- 
cree of heat at first applied. The reason that 
a live coal will not burn when suspended in- 
sulated in the air, is not, as Dr. Hutton sup- 
12 
of hydrogen is greater for oxygen than for 
the caloric which gives it its gaseous form ; 
but the oxygen is also combined with caloric, 
and there exists an attraction of cohesion be- 
tween the particles of the hydrogen gas and 
oxvgen gas; the same attraction subsists be- 
tween those of oxygen gas and hydrogen gas. 
Now the sum of all these affinities (namely, 
the affinity between hydrogen and c aloric, 
the affinity between oxygen and calyric, the 
cohesion of the particles of the hydrogen, and 
the cohesion of the particles of oxygen) is 
greater than the affinity between the hydro- 
gen and oxygen; and therefore no decom- 
position can take place. Let the affinity be- 
tween 
Oxygen and caloric be - 50 
Hydrogen and caloric - 50 
Cohesion of oxygen for hydrogen 4 
Cohesion of hydrogen 2 
Sum of quiescent affinities - 10f> 
The affinity of oxygen and hydrogen 105 
The quiescent affinities beinggreater than the 
divellent affinities, no decomposition can take 
place. 
Let now a quantity of caloric be added 
to the oxygen and hydrogen gas, it has the 
property of expanding them, and of course 
of diminishing their cohesion; while its affi- 
nity for them is so small, that it may be neg- 
lected. Let us suppose that it diminishes the 
cohesion of the oxygen 1, and of the hy- 
drogen also 1, their cohesion will now be 3 
and 1 ; and the quiescent affinities being only 
1 04, while the divellent are!05, decomposition 
would of course take place, and a quantity of 
caloric would thus be set at liberty to pro- 
duce tire same effects upon the neighbouring 
particles. 
Tlius, then, caloric acts only by diminish- 
ing cohesion ; and the reason that it is re- 
quired so much in gaseous substances, and 
in those combinations into which oxygen en- 
ters, is the strong affinity of oxygen and the 
other bases of the gases for caloric ; for owing 
to the repulsion which exists between the 
particles of that subtile substance, an effect is 
produced by adding large doses of it, con- 
trary to what happens in other cases. The 
more of it is accumulated, the stronger is the 
repulsion between its particles, and there- 
fore the more powerful is its tendency to fly 
off: and as this tendency is opposed by its 
affinity for the body and the cohesion of its 
particles, it must diminish both these attrac- 
tions. 
REPUTATION, or Fame. The security 
of reputation, or good name, from the arts of 
detraction and slander, is a right to which 
every man is intitled, by reason and natural 
justice ; since, without this, it is impossible 
to have the perfect enjoyment of any other 
advantage or right. I Black. 134. 
Reputation is properly under the protec- 
tion of the law, as all persons have an interest 
in their good name, and scandal and defama- 
tion are injurious to it ; though defamatory 
words are not actionable, otherwise than as 
they are a damage to the estate of tire person 
injured. Wood’s Inst. 37. 
REQUESTS, Court of, an antient court 
of equity, instituted about the nineteenth 
) ear of Henry VII. See Court. 
in the fortieth and forty -first years of queen 
Elizabeth, it was adjudged, upon solemn an- 
