F I S II E R Y. 
in fil'd have rented the fiftiei'y of that river from the khan 
of Derbert, at a certain Aim, which -of late years has 
been raifed to twenty-five thoufand roubles. In the fea- 
fon of their migration, there are fometime?, in one day, 
fifteen thoufand fturgeons taken with the hook, at the 
weirs formed acrofs the water ; nay, it is ftili mere re¬ 
markable, that, if the fifhermen are accidentally pre¬ 
vented from working during a Angle day, the fi'h accu¬ 
mulate in fuch numbers at the weir, as to fill the whole 
channel, infomuch that thofe which are uppermoft appear 
with their backs above water, in a river not lefs than 
four arfhines, or twenty-eight Englifli feet, deep, and 
fixty fathoms wide. The Perfian fifhery, which has been 
eflablifhed by the proprietors only a few years ago, and 
which, together with the rent, amounts to an expence of 
80,000 rubles, is faid to produce annually upwards of 
200,000 roubles. It might be (fill more lucrative, if the 
injudicious fifiiermen would preferve the great number 
of fifli, inftead of throwing them into the lea as ufelefs, 
after having collected their roes and air-bladders. Pallas’s 
Travels in 1793. 
The (burgeon, particularly that fpecies called the hufo, 
furniflies two important articles of commerce, caviare and 
ifinglafs.— Caviare is made two different ways : one is 
more granulated ; the other is called Jack caviar . To 
make the firfl, they granulate the eggs on a rough fieve or 
grating, to cleanfe them, and rub off the (kin and little 
blood-veflels which may adhere. Then they fait them 
in troughs, putting five pounds of fait to forty of the 
ova : the ova are left in the troughs for three quarters of 
an hour, or an hour, that they may imbibe the fait fuffi- 
ciently ; then they put them into a fine fieve for the brine 
to drain off; and, lafily, they are packed in tight calks.— 
The fack-caviar is made as follows : when the mem¬ 
branes are rubbed off the ova, they are put for half an 
hour in brine to foften them, during which time they 
muft be often fqueezed with the fingers to find when they 
are foft enough : when this is the cafe, they are put in a 
fine fieve to drain. Then they are put by half-pounds 
into conical facks or bags (whence the name), whofe 
pointed ends are tied to flicks lying croffwife, and they 
wring the bags to fqueeze out all the reft of the brine ; 
after this they are heaped into tubs, and a man with lea¬ 
ther (lockings tramples them with his feet: daftly, the 
tubs are clofed up, and pitched, that the ova may not get 
tainted.—There is alfo in the (hops a third fort of caviare, 
called Turkifh, or Armenian caviare: this method was 
brought into Turkey from Aftracan : they put the ova 
in layers into calks juft as they come from the fifti, put¬ 
ting over each a ftratum of fait, and fqueeze it down 
with the hand : when the cafk is full, they put on a cover, 
and lay Hones over it, to prefs the ova and fait into one 
mafs; and thus they are left from four to eight months ; 
that is, a calk prepared in fpring is fit for ufe in Septem¬ 
ber, and thofe prepared in autumn are fit in May. By 
this time the ova are moftly dry ; then, after covering 
them with fait and water, they are left once more to dry 
in the fun; laftly, they pack them in tubs for exporta¬ 
tion or home-confumption.—.The word fort of caviare is 
made and fold by the labourers for their own profit: they 
take for this purpofe the ova of dead fifli which are caft 
upon the (hore, or of thofe which are too fat ; they mix 
with thefe the fibrous remains of the eggs which have 
been palled through the fieve; they fait this in cafks, 
mixing them well with the fait; then they heap them up 
in wooden or copper veffels, and prefs them hard till they 
are pretty dry. 
The meiliod of making ijinglafs was long a fecret in the 
hands of the Ruffians; but was at length difeovered 
and the following account of it publifhed by Humphrey 
Jackfon, efq. in the 63d vol. of the Philofopliical Tranfi- 
aCtions. 
“All authors who have hitherto delivered precedes for 
making ichtliyocolla, fifli-glue, or ifinglafs, have greatly 
miftaken both its condiment matter and preparation. 
Vol. VII. No. 437. 
417 
To prove this affertion, it may not be improper to recite 
what Pomet fays upon the lubjeCl, as lie appears to be 
the princip 1 author whom the reft have copied. After 
deferibirig the fifli, and referring to a cut engraved from 
an original in hiscuftody, he lays: ‘As to the manner of 
making the ifinglafs, the finewy parts of the fifli are 
boiled in water till all of them be diflblved that will dif- 
folve ; then the gluey liquor is drained, and fet to cool. 
Being cold, the fat is carefully taken off, and the liquor 
itfelf boiled to a juft conflftency, then cut to pieces, and 
made into a twift, bent in form of a crefcent, as com¬ 
monly fold ; then hung upon a firing, and carefully dried.’ 
From this account, it might be rationally concluded, that, 
every fpecies of fifh which contained gelatinous principles 
would yield iftuglafs : and this parity of reafoning feems 
to have given rife to very hafty conclufions. In my firft 
attempt to difeover the condiment parts and manufacture, 
of ifinglafs, relying too much upon the authority of fome 
chemical authors whofe veracity I had experienced in 
many other inflances, 1 found myfelf confiantly difap. 
pointed. Glue, not ifinglafs, was the refu.lt of every 
procefs ; and although, in the fame view, a journey to 
Ruffia proved fruitlefs, yet a fteady perfeverance in the 
refearch proved not only fuccefsful as to this objeft, but, 
in the purfuit, to difeover a refinous matter plentifully 
procurable in the Britifh fiflieries, which has been found 
by ample experience to anfwer fimilar purpofes. And 
it is now no longer a fecret, that the lakes and rivers in 
North America are flocked with immenfe quantities of 
fifh, faid to be the fame fpecies with thofe in Mufeovy, and 
yielding the fined ifinglafs; the fiflieries whereof, under 
due encouragement, would doubtlels fupply all Europe 
with this valuable article. 
“ No artificial heat is neceffary to the production of 
ifinglafs, neither is the matter dilfolved for this purpofe ; 
for, as the continuity of its fibres would be deftroyed by 
folution, the mafs would become brittle in drying, and 
fnap fhort afunder, which is always the cafe with glue, 
but never with ifinglafs. The latter, indeed, may be 
refolved into glue with boiling water; but its fibrous re-' 
compofition would be found impracticable afterwards, 
and a fibrous texture is one of the mod diftinguifliing 
charaCteriftics of genuine ifinglafs. A due confideration 
that an imperfeCt folution of ifinglafs, called fining by' 
the brewers, poffeffed a peculiar property of clarifying 
malt-liquors, induced me to attempt its analyfis.in cold 
fubacid menftruums. One ounce and an half of good 
ifinglafs, deeped a few days in a gallon of dale beer, was 
converted into good fining, of a remarkably thick con¬ 
fidence : the dime quantity of glue, under fimilar treat¬ 
ment, yielded only a mucilaginous liquor, refembling 
diluted gum-water, which, inftead of clarifying beer, in- 
creafed both its tenacity and turbidnefs, and communi¬ 
cated other properties in no refpedt correfponding with 
thofe of genuine fining. On mixing three fpoonfufs of 
the folution of ifinglafs with a gallon of malt liquor, in 
a tall cylindrical glafs, a vaft number of curdly maffes 
became prefently formed, by the reciprocal attraction of 
the particles of ifinglafs and the feculencies of the beer, 
which, increafing in magnitude and fpecific gravity, ar¬ 
ranged themfelves accordingly, and fell in a combined 
date to the bottom, through the well-known laws of 
gravitation ; for, in this cafe, there is no elective attrac¬ 
tion, as fome have imagined, which bears the lead affinity 
with what frequently occurs in chemical decompofitions. 
If what is commercially termed long or Jkort Jlaplcd ifin¬ 
glafs be deeped a few hours in fair cold water, the en- 
twifled membranes will expand, and re-a (Fume their ori¬ 
ginal beautiful hue, and, by a dexterous addrefs, may 
be perfectly unfolded. By this fimple operation, we find 
that ifinglafs is nothing more than certain membranous 
parts of fifties, diverted of their native mucoGty, roiled 
and twifted into the forms above mentioned, and dried in 
open air. 
“The founds, or air-bladders, of frefn-water fifli in 
5 O general, 
*• 
