526 
P U T 
P U T 
being rubbed between the fingers, breaks 
into a coarse powder like earth. This is the 
last state observed in the putrefaction of 
animal substances ; they do not arrive at this 
term but at the end of a considerable time. 
During this decomposition, a variety of 
gaseous bodies are emitted ; these vary ac- 
cording to the substance exposed to putre- 
faction ; but they consist chiefly of hydrogen 
gas, holding sulphur, phosphorus, and car- 
bon, in solution ; of ammonia, water, and car- 
bonic acid, and perhaps also of azotic gas. 
Nitric acid seems in some cases to be formed 
anti emitted. The earthy-like residuum, 
which remains after the decomposition is 
completed, consists of the fixed parts of the 
animal substance, mixed with charcoal, oil, 
and ammonia. Thus it appears that putre- 
faction consi-ts in a total decomposition of 
the animal body; the elements of which 
combine together two and two, and thus 
term a new set of less complicated bodies. 
But any attempt to explain the manner in 
which tnese changes take place would be 
exceedingly imperfect indeed ; not only be- 
cause we are ignorant of the strength of the 
affinities of the different elementary parts of 
animal bodies for each other, but because 
we do not even know the manner in which 
these elements are combined, and conse- 
quently we cannot know by what particular 
forces these compounds are destroyed. 
In carcases buried in the earth, putrefac- 
tion takes place much more slowly ; but it 
is scarcely possible to observe its progress 
with accuracy. The abdomen is gradually 
dilated with elastic fluids which make their 
appearance in it, and at last it bursts and 
discharges a horribly fetid and noxious gas ; 
at the same time a dark-coloured liquid 
flows out. If the earth is very dry, and the 
heat considerable, the moisture is often ab- 
sorbed so rapidly, that the carcase, instead 
of putrefying, dries, and is transformed into 
what is called a mummy. 
Such, are the phenomena when dead bodies 
are left to putrefy separately ; but when 
great numbers of carcases are crowded to- 
gether in one place, and are so abundant as 
to exclude the action of external' air and 
other foreign agents, their decomposition is 
entirely the consequence of the reciprocal 
action of their ingredients themselves upon 
each other, and the result is very different. 
The body is not entirely dissipated or re- 
duced to mould, but all the soft parts are 
found diminished remarkably in size, and 
converted into a peculiar saponaceous mat- 
ter. This singular change was first accu- 
rately observed in the year 1786. 
The burial-ground of the Innocents in 
Paris having become noxious to those who 
lived in its neighbourhood, on account of 
the disagreeable and hurtful odour which it 
exhaled, it was found necessary to remove 
the carcases to another place, "it had been 
usual to dig very large pits in the burial- 
ground, and to fill them with the carcases of 
the poorer sort of people, each in its proper 
bier ; and when they were quite full, to cover 
them with about a foot deep of earth, and to 
dig another similar pit, and till it in the same 
manner. Each pit held between, one thou- 
sand and fifteen hundred bodies. It was in 
removing the bodies from these pits that this 
saponaceous substance was found. The 
V u % 
grave-diggers bad ascertained by long expe- 
rience, that about thirty years were required 
before all bodies had undergone this change 
in its full extent. Every part of the body 
acquired the properties of this substance. 
I lie intestines and viscera of the thorax had 
completely disappeared; but what is singular 
enough, the brain had lost but little of its 
size or appearance, though it was also con- 
verted into the same substance. 
This sponaceous matter was of a white 
colour, soft and unctuous to the touch, and 
melted, when heated, like tallow, it exhi- 
bited all the properties of a soap, containing, 
however, an excess of fatty matter. Four- 
cioy, who analysed it, found that it was com- 
posed of a fatly matter combined with am- 
monia, and that it contained also some phos- 
phat of lime and ammonia. Diluted acids 
decomposed it, and separated the fatty mat- 
ter ; alkalies and lime, on the other hand, 
drove off the ammonia. When exposed to 
the air, it gradually lost its white colour; the 
ammonia, in a great measure, evaporated ; 
and what remained had something of the 
appearance of wax. It absorbed water with 
great avidity, and did not part with it readily. 
Its white colour was owing to the presence 
ol that liquid. r I he oily matter, when sepa- 
lated by means of a diluted acid, was con- 
crete, and of a white colour, owing to the 
mixture of a quantity of water. ' When 
dried, itacquires a greyish-brown colour, with 
a lamellar and crystalline texture, like that 
of spermaceti ; but if it has been rapidly 
dried, it assumes the appearance of wax. it 
melts when heated to 126°; when properly 
puiified, by passing it through a linen cloth 
while fluid, it has scarcely any smell. Al- 
cohol does not act upon it while cold, but at 
the temperature of 120 1 it dissolves it : when 
the solution cools, the fatty matter precipi- 
tates, and forms a gritty mass. With alka- 
lies it forms a soap ; and when set on tire it 
burns precisely like oil or fat, only that it 
exhales a more unpleasant odour. 
Mr. Smith Gibbes found the same sub- 
stance in the pit into which animal matters 
are thrown at Oxford after dissection. A 
small stream of water constantly passes 
through this pit ; a circumstance which in- 
duced him to try whether animal muscle ex- 
posed to the action of a running stream nn- 
dei went the same change. The experiment 
succeeded completely: he attempted, in con- 
sequence, to lender this substance, to which 
lie gave the name of spermaceti, useful in 
those manufactures which require tallow; 
but the fetid odour which it constantly exhales 
was an insurmountable objection. Attempts 
vere indeed made to get over it; and a 
manufacture of Mr. Smith Gibbes*® sperma- 
ceti' was even .established at Bristol. 
Many attempts have been made to retard 
the destructive progress of putrefaction, in 
outer to preserve animal bodies either as 
food or for other useful purposes ; and se- 
veral methods have been ascertained which 
prevent it from operating for a considerable 
time. 
1. The freezing temperature is a complete 
preservation from putrefaction, as long as 
fhe animal substance is exposed to it. Ilence 
die common practice ot keeping meat in 
snow in the frozen climates of the north ; 
and of packing fish in ice, and sending them 
in that stale from Scotland to the London 
market. 
2. Almost all bodies which have a stron 
affinity for water retard putrefaction for 
longer or shorter time, doubtless by depriv- 
ing the animal substances ot their water, or 
pieventing that liquid from acting upon these 
bodies in its usual manner. In this wav the 
acids; sugar, alcohol, &c. seem to prevent or 
retard putrefaction. 
3. It is well known that common salt is a 
powerful antiseptic. Renee the practice of 
saltmg meat, and the length of tune which 
meat that has undergone this operation may 
be kept. Several other salts, especially nitre, 
possess the same property. In what n aimer 
these bodies act has not been ascertained ; 
but they undoubtedly produce some chemi- 
cal change upon the meat ; for they alter 
its taste, its colour, and other sensible pro- 
perties. 
4. Many aromatics, such as camphor, re- 
sins, volatile oils, bitumens, and other similar 
bodies, act with considerable efficacy in pre- 
serving animal bodies from putrefaction. 
Renee theii utility in embalming. In what 
the action of these substances consists has 
not been ascertained. Part ot their efficacy 
is doubtless owing to the rapidity with which 
the animal substances to which they are ap- 
plied lose their moisture ; and something 
may be ascribed likewise to their odour’ 
which keeps insects at a distance, and thus 
prevents the lodging of excrementitious mat- 
ter, which always acts powerfully as a putre- 
factive ferment. 
PU1 1 carqja, in botany, is a genus of In- 
dian plants, of which the characters, as given 
by sir William Jones in the Asiatic Research- 
es* vol. ii. p. 351. are these: The calyx is 
five-cleft ; the corolla has five equal petals; 
the pencarpium a thorny legumen and two 
seeds, the leaves oval and pinnated, and the 
stem armed. “ The seeds (says the learned 
president) are very bitter, and perhaps tonic; 
since one ot them, bruised and given in two 
doses, will cure the intermittent fever.” 
PUTTY, in the arts. When tin is melted 
in an qpen vessel, its surface soon becomes 
covered with a grey powder, which is an 
oxide of the metal, 'if the heat is continued, 
the colour of the powder gradually changes’ 
and at last becomes yellow. In this state it 
is known by the name of putty, and employ- 
ed m polishing glass and other hard sub- ' 
stances. 
1 utty is also a kind of paste compounded 
of whiting and linseed-oil, beaten together to 
the consistence of a thick dough, ft is used 
b\ glazieis for the fastening in the squares 
of glass in sash-windows, and by painters for 
stopping up the crevices and clefts in timber 
and wainscots, &c. 
PUZZULANA or Pozzolana, terra, or 
terras, is a greyish kind ot earth used in 
Italy for building under water. The best is 
found about Puteoli, I take, and Gumse, in 
the kingdom of Naples, from the first of 
which places it derives its name. It is sup- 
posed to be a volcanic product, composed of 
leterogeneous substances, thrown out from 
the burning mouths of volcanoes in the form 
of ashes; sometimes in such large quantities, 
and with so great violence, that whole pro- 
vinces have been covered with it at a con- 
siderable distance. This volcanic earth is of 
tn n 
