CHEMIS TRY. 
377 
balloon is found to contain (be liquid body which has 
come over, and the fecond bottle the gas abforbed by the 
water. 
Though, in cafe of neceflity, the balloon might be con¬ 
nected directly with the fecond bottle, in the feme man¬ 
ner as this bottle is connefted with the firfl:; yet the in¬ 
termediate bottle, with the tube of fefety, is of great ufe, 
as it enables us to judge of the progrefs cf the operation, 
and prevents the water, in cafe of an abforption of air in 
the retort, from patting into the balloon, where it would 
not only mix with the fluid, but might frequently, on ac¬ 
count of the great heat excited, produce an explofion of 
the balloon, and thus endanger the operator. With re- 
fpefit to the other circumftances and cautions, the fame 
obiervations are here applicable which we mentioned be¬ 
fore. 
This cpmpofition of Woulfe’s apparatus is made ufe 
of in the diftillation of ethers, and of edulcorated acids, 
but efpecially in the preparation of nitric acid, which, 
by way of example, we will proceed to deferibe. 
Four pounds of nitre, deprived by fufion of its water 
of cryftallization, were pulverized, and introduced into 
a glafs retort; the apparatus was compofed in the man¬ 
ner deferibed, and all the joinings, except that between 
the retort and the balloon, were luted with fat lute and 
ftrips of linen. Two pounds of the beft oil of vitriol (that 
of Nordhaufen) were then poured through the neck of 
the retort upon the nitre; the joining was immediately 
fecured, and diftillation commenced on the fend-bath by 
a heat at firfl: gentle, but gradually increafed till the retort 
became red-hot. The firfl; bottle contained three ounces 
of water for the innnerfion of the tube of fefety, and the 
fecond bottle one pint of water. The operation being 
finifhed, the balloon was found to contain twenty-feven 
ounces and two drams of the moll concentrated fuming 
nitric acid; in the firfl: bottle, five ounces fix drams of 
green fuming nitric acid; and, in the fecond bottle, 
twenty-fix ounces of Among blue nitric acid. 
Bottle. Water. Increafe. 
Balloon 27 ounces 2 drams 
No. 1 3 ounces a ounces 6 drams 
2 16 ounces 10 ounces 
It thus appears that there was obtained in this operation, 
befides the twenty-feven ounces two drams of fuming 
fpirit of nitre, in which the acid is bound by the water 
contained in the fulphuric acid made ufe of, twelve 
ounces fix drams of nitrous acid gas, combined with the 
nineteen ounces of the water employed. 
Second cafe. If, in a diftillation, where the bodies come 
over partly in the form of gas, and partly in the liquid 
ftate, we wife to obtain the gas feparately from the liquid 
over water or mercury, the retort is joined, as in the for¬ 
mer cafe, with the tubulated balloon, the collateral neck 
of which is conne&ed by means of a recurved tubulated 
communicating tube with a bell glafs in the pneumatic 
apparatus. The fubftance which comes over in the li¬ 
quid form, is here, as in the former cafe, collefted in the 
balloon; but the gafeous body paffes through the com¬ 
municating tube into the pneumatic apparatus, and rifes 
into the bell-glafs filled with vPater or mercury. By open¬ 
ing the fliort capillary tube of tine communicating tube, 
we (hall at all events prevent the tranfition of the water 
or mercury from the bell into the balloon. This compo- 
fition of Woulfe’s apparatus is frequently made ufe of 
in the analyfis of organized fubftances bv dry diftillation. 
Third cafe. If we know before-hand that the gafes 
to be obtained in a diftillation, befides the body in the 
liquid form, are two-fold, and that one is foluble in wa¬ 
fer, the other not, the two gafes may be obtained fepa¬ 
rately. To this end the apparatus is compofed exactly 
in the fame manner as in the firfl: cafe ; and a fecond bot¬ 
tle is moreover connected by means of the recurved comv 
municating tube with the pneumatic veflel. The liquid 
body, in this cafe, as in the two former, comes over di- 
refel-y into the balloon, but the gafeous bodies rife through 
VoL, IV. No. 2op. 
the communicating tube into the firfl receiver, and from 
thence into the fecond. The foluble gas is here abforbed 
by the water, and the infoluble gas paffes through the 
bent communicating tube into the belbof the tube. T he 
tube of fefety in the firfl. bottle indicates the progrels of 
(lie operation, and prevents the tranfition of the water 
into the balloon, but the capillary tube of the third com¬ 
municating tube is of great ufe in cafe the water of the 
tub fliould come over into the fecond bottle. If of the 
two the foluble gas be carbonic acid gas, we ufually ap¬ 
ply a foiution of cauftic pot-afh in the fecond bottle in¬ 
stead of pure water, becaufe it ablorbs this gas, mora 
perfeftly, and with greater fpeed. 
This conftruftion of Woulfe’s apparatus is principally 
made ufe of in the examination of organized fubftances by 
fire. Wood, for inftance, affords by dry diftillation, ail 
acidulous phlegm, an empyreumatic oil, inflammable and 
carbonic acid gas. To obtain thefe produ&s feparately, 
the wood is diftilled in the apparatus as above-mentioned, 
when the water and oil remain in the balloon, the carbo¬ 
nic acid is abforbed by the cauftic alkali, and the hydro¬ 
gen gas or inflammable air paffes over into the bell. Now, 
if the weight of all thefe bodies be afeertained, we find 
that the firm of the weight of the liquid body, of the 
gafes, and of the refidual carbon, is, fave a very final! 
lofs, equal to the weight of the wood made ufe of. 
Woulfe’s apparatus is likewife calculated for the im¬ 
pregnation of water with carbonic acid. For this pur- 
pofe, a bottle with two necks is connedled with a fecond 
bottle alfo with two necks, by means of a communicating 
tube with unequal ends, in liich a manner, that the lon¬ 
ger end enters the fecondbottle. After an optional quan¬ 
tity of pure water has been introduced into this fecond 
bottle, it is connefited in a fimilar manner with a third 
bottle, and this with a fourth. All the joinings having 
been fecured by lute of almonds, powdered chalk, and. 
highly diluted fulphuric acid, is alternately introduced 
through the fecond neck of the firfl: bottle, which.is clofed 
immediately after by means of a cork. The carbonic 
acid gas, generated during the foiution of the chalk in 
the fulphuric acid, comes over into the fecond bottle, 
and what is here not entirely abforbed by the water, pafles 
on to the third bottle, &c. After the operation has been 
continued for fome time, the water in the bottles is 
found to be highly feturated with the carbonic acid. The 
foiution of the chalk fhould be carried on very flowly, 
left the violent effervefcence, and the great degree of heat, 
caufe the fulphuric acid to "go over and mix with the wa¬ 
ter. 
In this manner a foiution of potafh or foda may be 
completely feturated with carbonic acid, and changed 
into a perfefit mild ftate. With a diluted foiution of pot- 
afli is prepared alfo the acidulous water for diffolving the- 
ftone ; if the ley be concentrated, very beautiful cryftals 
of the neutral carbonic acid felt will be formed during 
the operation. For this realon the communicating tubes 
fliould be always fomewhat wider in this operation, that 
they may not be fo ealily obftrudted by the cryftals. 
From this apparatus of Woulfe, feveral of thofe ex 
hibited in the preceding plates have been in part con. 
ftrudled, and adapted to particular experiments. 
VAN MARUM’s GAZOMETER. 
This is an improved apparatus, conftrudled by D „ 
Van Marum, of Haarlem, for the purpofe of producing 
water by the combuftion of hydrogen in oxygen gas; 
and is delineated in the Chemiltry Plate VII. The vef- 
fel, eleven inches in diameter, containing the air or gas 
to be employed, is reprefented at A. The mouth of it 
is clofed by a brafs cover ferewed upon it, and furnifhed 
with three cocks, B, C, D. On the cock B, is ferewed. 
a copper fyphon E F, having its end F ferewed upon 
another brafs tube open at the bottom, reprefented by 
the dotted lines G G, and which defeends,within the 
brafs cylinder H, which is open at the top.- To the 
5 D lower 
