T I T 
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T I P 
When a small quantity of iron only is to be 
ined, it is heated, and the tin rubbed on 
th a piece of cloth, or some tow, having 
it sprinkled the iron with some powdered 
sin, the use of which is to reduce the tin 
at may be oxydated. Any inflammable 
bstance, as oil for instance, will have in 
line degree the same effect, which is owing 
» their attraction for oxygen. 
[Tinning of copper. Sheets of copper 
iay be tinned in the same manner as iron, 
fopper boilers, saucepans, and other kitchen 
tensils, are tinned after they are made, 
'hey are first scoured, then made hot, and 
|e tin rubbed on as before with resin. 
Nothing ought to be used for this purpose 
ut pure grain tin; but lead is frequently 
lixed with the tin, both to adulterate its 
uality, and make it lie on more easily ; but 
; is a" very pernicious practice, and ought to 
e severely reprobated. 
\l'o xvhiten brass or copper by boiling. Put 
»e brass or copper into a pipkin with some 
bite tartar, alum, and grain tin, and boil 
Jem together. The articles will soon be- 
ome covered with a coating of tin, which, 
•hen well polished, will look like silver. It 
in this manner that pins, and many sorts of 
uttons, are whitened. 
TINNITUS aurium, a noise or buzzing 
i the ear, when it seems to receive sounds 
•hich do not exist, or at least which are not 
roduced by the motion of the external air ; 
nd the ear being filled with a certain species 
f sound, cannot admit other sounds, unless 
|iey are, very violent. The tinnitus is of two 
inds, the one proceeding from a distempera- 
jre of the organ of hearing, the other from a 
Border of the brain. 
■ TIPHIA, a genus of insects of the order 
ymenoptera. The generic character is, 
louth with a membranaceous rounded jaw; 
ie mandible arched and acute ; no tongue ; 
selers four, filiform, unequal, and inserted in 
ae middle of the lip ; antennae filiform, short, 
pnvolute ; sting concealed within the ab~ 
iomen. There are 27 species, 
i T I PUL A, a genus of insects of the order 
Iptera. The generic character is, mouth 
rched over by the upper jaw extended from 
he head ; palpi two, recurved, longer than 
he head ; proboscis recurved, very short. 
I The larger kinds of tipula? are, in general, 
llistingui hed by their lengthened bodies, ho : 
jzontaliy expanded wings, and the unusual 
ength and slenderness of their legs, which are 
Iso remarkably fragile; it being difficult to 
andie the insect without breaking some of its 
[mbs. The smaller kind have incumbent 
lings, and in habit or general appearance are 
jjiuch allied to gnats, and some are so very 
mall as scarcely to exceed the tenth of an 
nch in length. ’The larvae of this genus dif- 
er in habit, according to their different modes 
>f life, some being terrestrial, and others 
.quatic. They feed on the softer kind of ve- 
getable substances, as the fine fibres of roots, 
fee. &e. 
| The largest of the European tipulae, is the 
jpula rivosa of Linmeus, often measuring 
nore than an inch and a half in body ; and is 
distinguished by its wings, which are .trans- 
parent, with large dusky undulations inter- 
mixed with white towards the rib or upper 
xffie. This insect proceeds from a dusky or 
Ueyish larva of a lengthened form, and *des- 
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titute of legs. It is found beneath the roots 
of grass in meadows, gardens, & c. and in the 
months of July and August changes into a 
lengthened and pointed chrysalis of a dusky 
colour, out of which in September proceeds 
the complete animal. This is popularly 
known by the title of long legs, and is fre- 
quently seen in houses during the autumnal 
evenings, when it is remarkable tor the pro- 
pensity, in common with many other insects, 
of flying towards the flame of candles, and in 
consequence, often perishing in the blaze, 
Tipula hortorum, or the garden tipula, is 
of somewhat smaller size than the preceding, 
and is produced from a larva and chrysalis of 
similar appearance with those of the former 
kind, but of a darker or blacker colour. The 
larva is found under grass-roots, &c. The 
wings of this species are transparent, with ob- 
scurely marked whitish variegations. 
Tipula oleracea is a very common species, 
of nearly similar size with the preceding, and 
with transparent wings with a dusky rib or 
upper edge. Its larva inhabits garden-grounds, 
where it commits ravages among various 
plants. In its appearance it resembles those 
of the former kinds. It may be added, that 
the chrysalis, in most of the terrestrial insects 
of this tribe is furnished at the upper part 
with a pair of short hornlike processes, per- 
haps operating as a kind of spiracula; this 
particularity is however still more striking 
in those which belong to the aquatic kinds. 
The tipula cornicina is of middle size, and 
has transparent wings with a marginal dusky- 
spot, and the body yellow, with three longi- 
tudinal dusky streaks. Its larva, which is 
found in meadows, & c. is brown, with a flat- 
tened or truncated tail, beset with a certain 
number of radiating soft spines or processes ; 
and the chrysalis is slender, and furnished, 
as in most others, with minute spines about 
its segments, by the assistance of which it is 
enabled to elevate itself to the surface when 
the time of its ultimate change takes place. 
Tipula crocata is one of the few insects of 
this genus adorned with lively colours. It is 
of a polished black, with yellow rings round 
the abdomen. 
Of those in which the wings arc generally 
incumbent, the tipula plumosa, so named 
from its plumed antenna?, may serve as an ex- 
ample. This insect is of the size of a gnat, 
which it so much resembles in its general ap- 
pearance as to be frequently mistaken for 
one: its colour is a greenish brown. The 
larva is aquatic, bears a considerable resem- 
blance to those of the genus culex, as does 
likewise the chrysalis or pupa ; which, instead 
of lying dormant during this state, is loco- 
motive, playing about in the water, like the 
larva, and, at the time of its change, springs 
to the surface in order to give birth to the 
complete insect. 
Among the very small tipulae, none is more 
familiar than the elegant species called by 
Linnaeus tipula phalaenoides. 1 his minute 
fly is very frequently observed in great num- 
bers on windows during the decline of sum- 
mer, appearing principally in the evening. 
It has so little the appearance of a genuine 
tipula, that it would hardly be considered as 
belonging to this genus by a common spec- 
tator. Its general length is about the tenth 
of an inch ; and the wings, which are very 
large in proportion to the insect, are of an 
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oval shape, and of a grey colour, elegantly 
mottled or variegated with dusky sprCks’; 
the edges are deeply fringed with hair, and 
the nerves beset with oblong scales or fea- 
thers, and the whole insect, microscopically 
examined, exhibits a highly elegant appear- 
ance. 
Tipula hirta so much resembles the last, 
that it might perhaps be rather considered as 
a variety or sexual difference than truly dis- 
tinct. It is, however, a trifle larger, and of a 
darker colour. There can be little doubt 
that the larva? of these minute species are 
aquatic, but they seem to be hitherto un- 
described. There are 123 species. 
TITANIUM, a metal found in black 
sand, resembling gunpowder, in Cornwall, 
and upon examination it is found to possess 
the following properties: 
Its colour is orange-red, and it has a good 
deal of lustre. As it has been only obtained 
in very small agglutinated grains, neither its 
hardness, specific gravity, nor malleability, 
has been ascertained. It is one of the 
most infusible of metals, requiring a greater 
heat to melt it than can be produced by any 
method at present known. 
When heated in the open air, it combines 
readily with oxygen, and seems capable of 
forming three different oxides ; namely, the 
blue or purple, the red, and the white. 
The protoxide, which is of a blue or purple 
colour, is formed, when titanium is exposed 
hot to the open air, evidently inconsequence 
of the absorption of oxygen. 
The deutoxide or red oxide is found native. 
It is often crystallized in four-sided prisms. 
Its specific gravity is about 4.2; and it is 
hard enough to scratch glass. When heated 
it becomes brown, and when urged by a very 
violent fire some of it is volatilized. When 
heated sufficiently along with charcoal, it is 
reduced to the metallic state, 
The peroxide or white oxide may be ob- 
tained by fusing the red oxide in a crucible 
with four times its weight of potass, and dis- 
solving the whole in water. A white powder 
soon precipitates, which is the white oxide of 
titanium. Vauquelin and Hecht have shown 
that it is composed of 89 parts of red oxide 
and 11 parts of oxygen. 
Titanium does not seem to be capable of 
combining w ith sulphur. 
Phosphuret of titanium has been formed by 
Mr. Chenevix by the following process : lie 
put a mixture of charcoal, phosphat of tita- 
nium (phosphoric acid combined with oxide 
of titanium), and a little borax, into a double 
crucible, well luted, and exposed it to the 
heat of a forge. A gentle heat was first ap- 
plied, which w 7 as gradually raised for three 
quarters of an hour, and maintained for half 
an hour as high as possible. The phosphuret 
of titanium was found-in the Crucible in the 
form of a metallic button. It is of a white 
colour, brittle, and granular, and does not 
melt before the blow pipe. 
Vauquelin and Hecht attempted to com- 
bine it with silver, copper, lead, and arsenic, 
but without success. But they combined it 
with iron, and formed an alloy of a grey co- 
lour, interspersed with yellow-coloured’ bril- 
liant particles. This alloy they were not 
able to fuse. 
The affinities of the oxides of titanium are, 
