CHEMISTRY. 
The matrafs is placed in «a bath of boiling water, and 
when, from the thermometer, we judge the liquid is raifed 
to a proper temperature, the matrafs is placed in the ca¬ 
lorimeter. The calculation of the products, to determine 
the fpecific caloric of thel'e fluids, is made as above-di- 
reCted, taking care to deduCt from the water obtained the 
quantity which would have been produced by the ma¬ 
trafs alone, which muft be afcertained by a previous ex¬ 
periment. 
The various parts of the calorimeter, adapted to thefe 
feveral purpofes, are delineated in the plate, as follows : 
Fig. i, 2, and 3, give a perfpeCtive view of the appara¬ 
tus, and exhibit a vertical and an horizontal feCtion of 
the fame; ff ff, in fig. 2, fhews the interior cavity in 
which the fubftances are to be placed ; it is compofed of 
a grating, or cage of iron wire, fupported by feveral iron 
bars ; this grating, or cage, for the fake of diftinCtnefs, 
is reprefented feparately at fig. 4, with its lid or cover; b b, 
in fig. 2 and 3, denote the middle cavity, deftined to con¬ 
tain the ice to be melted; this is fupported by the grate 
mm> under which is placed the fieve nn. Thefe two are 
reprefented feparately at fig. 5 and 6. In proportion as 
the ice is melted, the water runs into the conical funnel 
ccd, fig. 2. This water may be retained or let out at 
pleafure by the ftop-cock u. The external cavity aaaa, 
fig. 2 and 3, is filled with ice, to prevent any effect from 
external heat on the ice in the cavity b b b b ■, fig. 7, is 
the lid to cover the machine. The fubftances to be ope¬ 
rated upon are placed in the thin iron bucket, fig. 8, the 
cover of which has an opening fitted with a cork, into 
which a fmall thermometer is fixed. When acids, are 
ufed, they are put into a glafs veflfel, or matrafs, fig. 9, 
which has alfo a fmall thermometer fitted to its neck, 
and is alfo fupported by the fmall ring, fig. 10. 
On the CHEMICAL CHARACTERS. 
Language, in many cafes, is incapable of exprelling 
our conceptions with that rapidity and perfpicuity, 
which we fometimes find neceffary for an inflantaneous 
communication of our ideas. Writing is Hill flower than 
fpeech, in the ordinary mode of exprefling things by 
words at length ; hence the introduction of figns and 
fymbols, to exprefs whole fentences by Angle marks. 
The chemical characters are an inftance of this; they 
were invented by the earlier chemifts, to fave time in 
writing the names of fubftances that frequently occurred, 
in the fame manner as we avoid repetitions by the ufe of 
pronouns, or of exprefling firms in words, which are 
more expeditioufly let down in figures. 
We need not have recourfe to the remote field of Chi- 
nefe literature, to fliew how admirably the (implicit.)', re¬ 
lative poiition, and connection of characters, are calcu¬ 
lated to exprefs ideas, at one glance of the eye, with a 
degree of accuracy and precifion not to be obtained by 
the ufe even of many written words. Neither need we 
recur to the fcience of algebra, where, by the ufe of cha¬ 
racters, the mind receives the proof, and aflents to pro- 
pofitions alrnoft inftantaneoufly, which would have re¬ 
quired a long feries of verbal deductions in any other 
way. Our own fcience, chemiftry, will afford us in- 
ftances of the moll linking nature. The tables at the 
end of Bergman's Efiay on the Affinities, exhibit, in a 
fpeedy and intelligible manner, the greater part of many 
volumes of chemical refults; and it is certainly eafy, by 
a Ample combination of chemical and algebraical cha¬ 
racters, to write the whole contents of any chemical 
work in a fmall compafs; yet fo full, clear, and p erfpi- 
cuous, that whole pages may be read and underftcod in 
a few feconds. 
Characters are either entirely arbitrary, or they have 
fome refemblance to the idea they reprefent. The latter 
property is naturally aimed at, where it can be obtained, 
becaufe it cannot but tend to afiilt the memory. Thus a 
number of dots were ufed to denote fand or powder; the 
figure of a retort, to denote the retort ; and the combi- 
395 
nation of characters is ufed to denote fimilar combina¬ 
tions of the fubftances they reprefent. Very little of 
fyftem appears in the ancient characters of chemifts: 
thofe of the alcliemiits were certainly intended to fcreen 
their fcience under a myfterious veil; yet many of the 
characters of Bergman feem chiefly grounded on thefe 
ancient characters, with additions and improvements. 
But the characters of Halfenfratz and Adet are fyftema- 
tical throughout, and are now generally adopted, 
Thefe two chemifts w'ere employed by the Academy of 
Sciences at Paris, in 1787, to correct and reform the 
chemical charaCteriftics. Their official charge was to 
methodize and illuftrate two problems or parts: 1. To 
find out general characters, or fymbols, by which the 
then known Ample fubftances, or confidered as Ample, 
as well as thole which may be difcovered in future, may¬ 
be exprefied in a conftant and uniform manner. 2d. To 
combine thofe general characters in fuch a manner, that, 
with regard to compounds of the Ampler fubftances, the 
number, nature, and proportion of their component 
principles, may be diftinCtly exprefied by that union of 
the primitive fymbols. 
In order to folve the firftpartof the problem, Haflen- 
fratz and Adet divided the Ample fubftances, according 
to the modern difcoveries, into four genera. To tilde 
they added two other genera; one for fubftances fup- 
pofed to be compound, and whole decompofition is al¬ 
ready forefeen; the other for compound bodies, with 
the conllituent principles of which we are as yet unac 
quainted. 
Firft Genus.— Subfiances <u>hich appear to enter into 
the Compofition of the greater number of Bodies. For 
thefe they have chofen a fliort ftraight line, which can 
have four different pofitions. The vertical, which they 
have adopted for exprefling caloric; the horizontal, 
adopted for oxygen ; the oblique, from the right down¬ 
wards to the left, the character of azot or nitrogen; 
laftly, the oblique from the left to the right, which may 
ferve for future difcoveries, as well as the zigzag or wa¬ 
ving line in thefe four pofitions.—By a vertical zigzag 
line they exprefs light. 
Second Genus.— Alkaline and Earthy Subfances. Thefe 
are denoted by an equilateral triangle. With its vertex 
upwards, it Agilities the alkalis; and with its vertex 
downwards, it is appointed to indicate the earths.—To 
diftinguilh the individual fubftances of each of thefe fpe- 
cies, the initial letter of their Latin name is inferabed in 
the triangle : as P. for potaflinum, S. for foda, C. for 
calx, A. for argilla. But, whenever two or more of 
thefe have the fame initial letter in their name, the next 
conionant in order is added. Thus llrontian-earth, is 
diftinguifhed by St. from Alex, marked only by S.— 
Ammoniac is left out from the alkalis, becaufe its con- 
ftituent parts are at prefent known. The initials of the 
Latin names were chofen, becaufe they are known in 
every country, and the characters were defigned to be 
univerfal, otherwife each nation would have a difference 
in thefe characters. 
Third Genus.— Inflammable Subfla/ices. To fignify 
thefe, the femicirclehas been taken, with its four different 
pofitions. Opening to the left for hydrogen; opening 
to the light for carbon ; opening downwards for phoi- 
pliorus; opening upwards for lulphur. By doubling 
this femicircle, inflammables of future dilcovery may 
be denoted. Thus Dr. Pearfon has lately employed two 
femicircles, placed vertically upon each other, and open¬ 
ing to the left, for reprefenting the diamond, which is 
now confidered as the purelt carbon. 
Fourth Genus.— Metallic Subflanccs, for which the 
circle has been chofen. Gold has preferved its ancient 
fign, a circle with a point in the centre, heretofore ufed 
to reprefent Sol, the fun. The other metals are diftin- 
guifhed by inferting the firft letter of their Latin name, 
but to avoid confulion in metals having the initial in their 
name, the next confonant in order, that is to fay, begin-. 
ning 
