TIT 
ihort, convolute ; sting concealed within 
the abdomen. There are about twenty- 
•even species, in two divisions : A. jaw 
vaulted; lip membranaceous, emarginate. 
B. jaw rounded ; lip horny, three-toothed. 
TIPULA, in natural histoiy, crq,ne-fly, a 
genus of insects of the order Diptera, Mouth 
with a very short membranaceous probos- 
cis, the back grooved and receiving a bris- 
tle; two feelem, incurved, filiform, and 
longer than the head ; the antennae are 
mostly filiform. There are nearly one 
hundred and fifty species, in two sections, 
distinguished by their wings. Tlie insects 
in the division A have their wings expand- 
ed ; those in B have them incumbent. 
Most of the insects of this genus are very 
like tlie gnat; they feed on various sub- 
stances : the larv® are without feet, soft, and 
cylindrical, with a truncate toothed head ; 
and feed on the roots of plants : the pupa 
is cylindrical, tvvo-liorned before, and tooth- 
ed beliind. Tlie largest of the European 
tipute is T. rivosa, it is found frequently an 
inch and half in body, and is distinguished 
by the colour of its wings which are trans- 
parent, with large dusky undulations, inter- 
mixed with white towards the rib, or upper 
edge. This insect proceeds from a greyish 
larva, found beneath the roots of grass in 
meadows, gardens, &c. and, in the months 
of July and August it changes into a 
lengthened chrysalis, out of which, in Sep- 
tejiibei', proceeds the complete animal. 
This is known by the title of long-legs, and 
is frequently seen in houses during autum- 
nal evenings, when, if it be possible, it will 
destroy itself by flying into the flame of a 
lighted candle. This propensity is common 
to many insects. T. tritici, is a very minute 
insect. The antennas are moniliform, lonn-er 
than the thorax ; legs very long. The larva 
is found in the ears of wheat, to whicli it is 
very injurious. 
TITANIUM, is a metal of a copper 
red colour, very difficult of fusion, soluble 
in muriatic acid, from which it may be pre- 
cipitated by a tincture of galls. This metal 
■was discovered, in 1793, by Klaproth. He 
obtained it from a mineral called red schorl. 
In this mineral he found the oxide of ’a me- 
tal different from any other then known. 
To this, from Meriachan in Cornwall, 
where it was found, he gave the name of 
menaclianite, but he had not succeeded in 
reducing it to the metallic state. Klaproth 
afterwards analyzed the menachanite, arid 
found that it was precisely the same as the 
ftxjde of the metal which he discovered in 
TIT 
red schorl. To this metal he gave the name 
of titanium. This metal has been found only 
in the state of oxide. Red schorl consists 
entirely of this oxide. It has been found 
in different countries, as in Spain, Fiance, 
and Hungary. It is disseminated in the fine 
specimens of rock-crystal wliich are brought 
from Madagascar, crystallized in long bril- 
liant needles ; the form of the primitive 
crystal being a six sided pi ism with two- 
sided summits ; that of the molecule is a 
triangular prism, with right-angled isosceles 
bases. It is of a red colour, of different 
shades. It is brittle, but the fragments are 
so hard as to scratch glass, The specific 
gravity is from 4.1 to 4.2. Tlie other mi- 
iieral, to which Klaproth has given the 
name of titanite, is composed of oxide of 
titanium, silica, and lime, nearly in equal 
proportions, Its specific gravity is 3.5, 
Titanium was obtained by Vauquelin, by 
reducing the native red oxide. He mixed 
together 100 parts of this oxide with 50 of 
calcined borax, and 50 of charcoal, formed 
into a paste with oil ; and exposed the whole 
to the heat of a forge raised to 166° Wedg- 
wood. By tills process he obtained a dark- 
coloured, agglutinated mass, having a bril, 
liant appearance on the surface. Titanium 
obtained in this way, is of a reddish yellow 
colour, shining and brilliant on tlie surface, 
and equally brilliant in some of its internal 
cavities. 
Titanium seems to be one of the most 
infusible metals known. When the red 
oxide is exposed to heat in a crucible, it 
Ip^es its lustre. By the action of the blow- 
pipe it is deprived of its transparence, and 
becomes of a greyish-white colour. On 
charcoal it becomes still more opaque, and 
of a slate-grey. The artificial carbonate of 
thallium, exposed to heat in a crucible, loses 
tso its weight, becomes yellow, and as it 
cools resumes its white colour. Titanium 
enters into combination with phosphorus, 
and forms with it a phosphuret. This was 
prepared by M. Chenevix, by exposing a 
mixture of phosphate of titanium, charcoal, 
and a little borax, in a crucible, to a very 
strong heat. The phosphuret which he ob- 
tained was in the form of a metallic button, 
of a pale white colour, brittle, and granular, ' 
and infusible by the action of the blow-pipe. 
This metal enters into combination with 
the acids, and forms salts with them. 
If into a phial, filled with muriate of tita- 
nium, there is put a stick of tin, and the 
bottle enclosed w'ith a stopper, a faint rose 
colour will soon be visible in that part of 
s 
