42 
LAC 
LAC 
LAC 
turbid appearance ; and on standing there 
were clouds just perceptible. 
Sulphuret of lime occasioned a white pre- 
cipitation, but no sulphureted hydrogen gas 
was perceptible by the smell. 
Tincture of galls produced a green pre- 
cipitation. 
Sulphatof iron produced a purplish colour, 
but no precipitation ; nor was any precipitate 
formed by the addition first of a little vinegar 
and then of a little potass to the mixture. 
Acetat of lead occasioned a reddish pre- 
cipitation, which redissolved on adding a 
little nitric acid. 
Nitrat of mercury produced a whitish tur- 
bid lirpior. 
Oxalic acid produced immediately the 
precipitation of white acicular crystals owing 
probably to the presence of a little lime in 
the liquid. 
Tartrat of potass produced a precipitation 
not unlike what takes place on adding tar- 
taric acid to tartrat of potass; but it did not 
dissolve again on adding potass. 
LACE, in commerce, a work composed of 
many threads of gold, silver, or silk, inter- 
woven one with the other, and worked upon 
a pillow with spindles, according to the pat- 
tern designed ; the open work being formed 
with pins, which are placed and displaced as 
the spindles are moved. 
Method of cleaning gold-lace and embroi- 
dery when tarnished . — For this purpose alka- J 
line liquors are by no means to be used ; for i 
while they clean the gold they corrode the 
silk, and change or discharge its colour. Soap ' 
also alters the shade, and even the species of 
certain colours. But spirit of wine may be 
used without any danger of its injuring either j 
the colour or quality of the subject ; and in 
many cases proves as effectual for restoring 
the lustre of the gold as the corrosive deter- 
gents. 
But though spirit of wine is the most inno- 
cent material that can be employed for this 
purpose, it is not in all cases proper. 'The 
golden covering may be in some parts worn 
off; or the base metal, with which it has been 
inlquitously alloyed, may be corroded by the 
air, so as to leave the particles of the gold 
disunited ; while the silver underneath, tar- 
nished to a yellow* hue, may continue a to- 
Jerable colour to the whole: in which cases 
it is apparent that the removal of the tarnish 
would be prejudicial to the colour, and make 
the lace or embroidery less like gold than it 
was before. 
Lace, bone, a lace made of fine linen 
thread or silk, much in the same njanner as 
that of gold anti silver. The pattern of the 
lace is fixed upon a large round pillow, and 
pins being stuck into the holes or openings in 
the pattern, the threads are interwoven by 
means of a number of bobins, made of bone 
or ivory, each of which contains a small 
quantity of fine thread, in such a manner as 
to make the lace exactly resemble the pat- 
tern. There are several towns in England, 
and particularly in Buckinghamshire, that 
carry on this manufacture ; but vast quanti- i 
ties of the finest laces have been imported 
from Flanders. 
LACERTA, lizard, a genus of the am- ; 
phibia class, and of the order of reptiles : tiie 
generic character is, body four-footed, elon- 
gated, tailed; without any secondary integu- 
ment. 
This numerous genus may be divided into 
the following sections, viz. 
1 . Crocodiles, furnished with very strong 
scales. 
2. Guanas, and other lizards, either with 
serrated or carinated backs and tails. 
3. Cordyles, with denticulated, and some- 
times spiny scales, either on the body or tail, 
or both. 
4. Lizards proper, smooth, and the greater 
number furnished with broad square, scales or 
plates on the abdomen. 
5. Chameleons, with granulated skin, large 
head, long missile tongue, and cylindric tail. 
6. Geckos, with granulated or tuberculated 
skin, and lobated feet, • with the toes lamel- 
lated beneath. 
7. Seinks, with smooth, fish-like, scales. 
8. Salamanders, newts, or cits, with soft 
skins, and of which some are water-lizards. 
9- Snake-lizards, with extremely long bo- 
dies, very short legs, and minute feet. 
The above divisions neither are, nor can 
be, perfectly precise ; since species may oc- 
cur which may, with almost equal propriety, 
be referred to either of the neighbouring sec- 
tions ; but, in general, they will be found 
useful in the investigation of the species. The 
following are the most noted: 
1. Lacerta crocodilus, or crocodile. The 
crocodile, so remarkable for its size and pow- 
ers of destruction, has In ail ages been re- 
garded as one of the most formidable ani- 
mals of the warmer regions. It is a native 
of Asia and Africa, but seems to be most com- 
mon in the latter; inhabiting large rivers, as 
the Nile (see Plate Nat. Hist. iig. 237), the 
Niger, &c. ami preying principally on fish, 
but occasionally seizing on almost every ani- 
mal which happens to be exposed to its rapa- 
city. The size to which the crocodile some- 
times arrives is prodigious ; specimens being 
frequently seen of 20 feet in length, and in- 
stances are commemorated of some which 
have exceeded the length of 30 feet. The 
armour with which the upper part of the 
body is covered may be numbered among the 
most elaborate pieces of nature’s mechanism. 
In the full-grown animal it is so strong and 
thick as easily to repel a musket-ball ; on the 
lower parts it is much thinner, and of a more 
pliable nature : the whole animal appears as 
if covered with the most regular and curious 
; carved work : the colour of a full-grown cro- 
| codile is blackish-brown above, and yellow- 
i ish-white beneath ; the upper parts of the 
j legs and the sides varied with deep yellow, 
1 and in some parts tinged with green. In the 
! younger ahimals the colour on the upper 
parts is a mixture of brown and pale yellow, 
! the under parts being nearly white : the eyes 
' are provided with a nictitating membrane, or 
transparent moveable pellicle, as in birds : 
the mouth is of vast width, the rictus or gape 
having a somewhat flexuous outline, and both 
jaws being furnished with very numerous 
sharp-pointed teeth, of which those about the 
middle part of each jaw considerably exceed 
the rest in size, and seem analogous to the 
canine teeth in the viviparous quadrupeds or 
mammalia: the number of teeth in each jaw 
is 30, or more; and they are so disposed as 
to alternate with each other when the mouth 
i* dosed : on taking out the teeth and ex- 
amining the alveoli, it lias been found that 
small teeth were forming beneath, in order 
to. supply the loss of the others when shed : 
the auditory foramina are situated on the top 
of the head, above the eyes, anil are mode- 
rately large, oval, covered by a membrane, 
having a longitudinal slit or opening, and 
thus in some degree resembling a pair of 
closed eyes: the legs are short, but strong 
and muscular: the fore feet have live toes, 
and are unwebbed : the hind feet have only 
four toes, which are united towards their base 
by a strong web : the two interior toes on 
each of the fore feet, and the interior one of the 
hind feet, are destitute of claws -. on the other 
toes are strong, short, and curved claws: the tail 
is very long, of a laterally compressed form, 
and furnished above with an upright process, 
formed by the gradual approximation of two 
elevated crests proceeding from the lower 
pait of the back. 
The crocodile in a young state is by no 
means to be dreaded, its small size and weak- 
ness preventing it from being able to injure i 
any of the larger animals : it therefore con- 
tents itself with lish and other small prey ; 
and such as have occasionally been 'brought 
to Europe are so far from being formidable 
or ferocious, that they may be generally 
handled with impunity, and either from weak- 
ness, or the effect of a cold climate, seem 
much inclined to torpidity ; but in the glow- 
ing regions of Africa, where it arrives at its 
full strength and power, it is justly regarded 
as the most formidable inhabitant of the 
rivers. It lies in wait near the banks, and 
snatches dogs and other animals, swallowing j 
them instantly, and then plunging into the i 
flood, and seeking some retired part, where 
it may lie concealed till hunger again invites : 
it to its prey. In its manner of attack it is 
exactly imitated by the common lacerta pa- 
1 ust r is, or water-newt, which, though not 
more than four or live inches long, will with 
the greatest ease swallow an insect of more 
than an inch in length ; and that at one sin- 
gle effort, and with a motion so quick, that 
the eye can scarcely follow it. It poises it- 1 
self in the water, and having gained a conve- 
nient distance, springs with the utmost cele- 
rity on the insect, and swallows it. If, there* 1 
fore, a small lizard of four or live inches only i 
in length can thus instantaneously swallow an 
animal of a fourth part of its own length, we 
need not wonder that a crocodile of *18, 2.0, j 
or 25, feet long, should suddenly ingorge a 
dog or other quadruped. 
Crocodiles, like the rest of the lacerta*, are 
oviparous: they deposit their eggs in the] 
sand or mud near or on the banks of the ; 
rivers they frequent, and the young when 
hatched immediately proceed to the w ater ; 
but the major part are said to be commonly 
devoured by other animals, as ichneumons^ 
birds, &c. The egg of the common nilotic 
crocodile is not much larger than that of a 
goose, and in external appearance bears a 
most perfect resemblance to that of a bird ; j 
being covered with a calcareous shell, under 
which is a membrane. When the young are 
first excluded the head bears a much larger 
proportion to the body than when full-grown. 
The eggs, as welt as the flesh of the crocodile 
itself, are numbered among the delicacies of 
some of the African nations, and are said to 
form one of their favourite repasts. 
In the large rivers of Africa crocodiles are 
said to be sometimes seen swimming toge-] 
tlier in vast shoals, and resembling the trunks, 
of so many large trees floating on the water. 
