805 
T 0 N. 
T O ? 
that eminent ornithologist) inhabit the warmer 
parts ot America. They vary considerably 
in their bills as to breadth, but all of them 
have a certain flatness, or depression, which 
is peculiar. They have a great affinity to the 
flycatchers ; and, indeed, to speak the truth, 
the two genera run much into one another. 
However, in one thing they differ materially ; 
for in the tody, the outer and middle toes are 
much connected, whereas in the flycatcher 
genus they are divided to their origin.” 
r l OLUIFERA, the balsam of tolu-tree, a 
genus of plants of the class decandria, and 
order monogynia. The calyx is five-toothed, 
bell-shaped; petals five, obcordate; style 
none. There is only one species, the balsa- 
mum. This tree grows to a considerable 
height: it sends off numerous large branches, 
■and is covered with rough, thick, greyish 
bark; the leaves are elliptical or ovate, en- 
tire, pointed, alternate, of a light-green co- 
lour, and stand upon short strong footstalks ; 
the flowers are numerous, and produced in 
lateral racemi. 
It grows in Spanish America, in the pro- 
wince of Tolu, behind Carthagena, whence 
we are supplied with the balsam. This bal- 
sam is obtained by making incisions in the 
bark of the tree, and is collected into spoons, 
which are made of black wax, from which it is 
/poured into proper vessels. 
This balsam is of a reddish-yellow colour, 
■transparent, in consistence thick and tena- 
cious. By age it grows so hard and brittle, 
that it may berubbed into a powder between 
the finger and thumb. 'Its smell is extremely 
fragrant, somewhat resembling that of lemons. 
Its taste is warm and sweetish, ancl on being 
chewed, it adheres to the teeth. See Bal- 
sams. 
This balsam possesses the same general vir- 
tues with the balsam of Gilead, and that of 
■Peru. It is, however, less heating and stimu- 
lating, and may. ti-erefo'e, be employed with 
more safety. It has bien chiefly used as a 
pectoral, and is -said to be an efficacious cor- 
roborant in gleets and seminal weaknesses. 
It is directed by the Pharmacopoeias in the 
syrupus tolutanus, tinctura tolutana, and sy- 
rupus balsamicus. 
- TOMBAC, a metal composed of copper 
and arsenic. See Arsenic. 
TOMERS, a genus of the class and order 
dodecandria monogynia. The involute is four 
or five-leaved ; calyx none; corolla five-pe- 
tailed; nect. scales live; berry one-seeded. 
1 here are three species, of which the sabipere 
or tallow-tree ot China is the most remark- 
able. The leaves and twigs of this tree 
abound in a viscid juice, and being bruised 
-and macerated in wafer, render it glutinous, 
and it is used by the natives to work up their 
plaister. A great quantity of thick white oil 
is extracted from the berries, of which can- 
dles are made resembling wax or spermaceti. 
1 ON weight, 20 hundred. See Weight. 
TONE, or Tune, in music, a property of 
sound whereby it comes under the relation of 
grave ancl acute ; or it is the degree of eleva- 
tion any sound has, from the degree of swift- 
ness of the vibrations of the parts of sonorous 
bodies. See Sound, 
Tone is more particularly used for a cer- 
tain degree or interval of tune, whereby a 
sound maybe either raised or lowered from 
one extreme of a concord to the other, so as 
still to produce true melody, 
T O N 
TONGUE. See Anatomy. 
r I ONNAGE, a custom or impost due for 
merchandize brought or carried in tons from 
or to other nations after a certain rate in 
every ton. 
Tonnage. The usual method of findinp 
the tonnage of any ship is bv the following 
rule:— Multiply the length of the keel by t-he 
breadth of the beam, and that product by 
half the breadth of the beam : and divide the 
last product by 94, and the quotient will be 
the tonnage. 
Ship's keel 72 feet ; breadth of beam 24 
feet. 
72 x 24 x 12 . 
-=120.6 tonnage. 
94 
1 he tonnage of goods and store is taken 
sometimes by weight, and sometimes by mea- 
surement ; and that i elhod is allowed to the 
vessel which yields the most tonnage. In 
tonnage by weight, 20 cwt. make 1 ton. In 
tonnage by measurement, 40 cubic feet are 
equal to 1 ton. All carriages, or other stores to 
be measured by tonnage^ are taken to pieces, 
and packed in the manner which will occupy 
the least room on board ship. All ordnance, 
whether brass or iron, is taken in tonnage by 
its actual weight. Musket-cartridges in bar- 
rels or boxes, all ammunition in boxes, and 
other articles of great, weight, are taken in 
tonnage according to their actual weight. 
The following is the tonnage allowed to the 
military officers of the ordnance embarked 
for foreign service, for their camp-equipage 
and baggage : 
For a field officer - 5 tons. 
For a captain - 3 do. 
For a subaltern - l^do. 
TONSELLA, a genus of the class and 
order triandria monogynia. The calyx is 
five-parted; petals five ; nect. pitcher-shap- 
ed; berry one-celled, four-seeded. There 
are two species, trees of the West Indies. 
TONSILS. See Anatomy. 
TONSURE, in ecclesiastical history, a 
particular manner of shaving or clipping the 
hair of ecclesiastics or monks. 
r ] lie antient tonsure ot the clergy was 
nothing more than polling the head, and cut- 
ting the hair to a moderate degree, for the 
sake of decency and gravity ; and the same 
observation is true, with respect to the ton- 
sure of the antient monks. But the Ro- 
manists have carried the affair of tonsure 
much farther ; the candidate for it kneeling 
before the bishop, who cuts his hair in five 
different parts of the head. viz. before, be- 
hind, on e.icii side, and on the crown. 
TONTINE, a species of increasing an- 
nuity on which money is sometimes borrowed, 
either for the service of the state, or for 
erecting bridges, churches, theatres, taverns, 
and other expensive buildings. • It is usually 
divided into a certain number of shares, for 
each of which a life is nominated ; and a cer- 
tain annual sum being set apart for payment 
of interest on the money advanced, the same 
sum is to continue to be annually divided 
among the surviving nominees, by which 
means their annuities increase as the number 
0 t shares are reduced, till the whole are ex- 
te- 
rn T he first attempt in this country to raise 
t a oney for the public service on this uncer- 
in kind of interest, was, in 1693; but though 
in this instance the annuity was more deter- 
minate than in the generality of such plans, 
as the subscribers were certain of 10 per 
cent, for the first seven years, it did not suc- 
ceed, only 108,100/. being advanced out of 
a million intended to be raised. 
In 1757, an attempt was made to raise a 
loan by a tontine scheme; and in 1765, a 
tontine formed part of a project for funding 
navy and victualling bills; both these plans 
were unsuccessful ; and the tontine formed in 
the year 1789, which was the last attempt to 
raise a public loan in this way, experienced a 
similar fate, as not half the proposed number 
of shares were disposed of. 
A variety of tontine schemes for short pe-* 
nods of five or seven years, have of late been 
set on foot, to the delusion of those who have 
been induced to subscribe to them. 
Mr. W. Morgan has shewn the folly of 
these speculations. He observes, that in the 
short term of seven years, the accumulation 
of money at simple and compound interest, 
is much the same, and the decrements of 
life are so inconsiderable, as to produce little 
or no effect in increasing this accumulation. 
A weekly payment of sixpence improved at 
4 per cent, compound interest lor seven 
years, will amount to 10/. 5s. 3d. but at sim- 
ple interest it will amount to 10/. 3, s. 10 d., 
and at no interest at all, to 9 /. 2s. The ad- 
dition, therefore, to the principal from the 
mere operation of compound interest, is so 
inconsiderable, that were all the subscribers 
to live to the end of the term, each share 
would be increased by this means only 
1/. 3s. 7 d. With respect to the advantage 
arising from survivorship, let it be supposed 
that the number of subscribers to the tontine 
is 10,000, consisting of persons of all ages 
under 60 years. According to the table of 
probabilities of life at Northampton, 8647 of 
those persons will survive a term of seven 
years;* so that if the whole 10,000 lived to 
make their last payment, and none of them 
died till just before the final distribution of 
the stock, the share of each survivor would 
be no more than 11/. 17s-. 6d. But it is to 
be observed, that these lives will be con- 
tinually dying from the time of the first sub- 
scription to the conclusion of the tontine; 
and that these deaths, by lessening the week- 
ly contributions, will reduce the share of 
each survivor to II/. 11$. nearly. When 
tire expences of management are also de- 
ducted, and allowance is made for the loss 
which may be sustained by investing the 
money in the public funds, it is more than 
probable that the shares will fall greatly be- 
low the sum just stated, and that the surviv- 
ing members will, at the end of seven years, 
have the mortification of finding that they 
barely receive the money they have paid, 
after having endangered the loss of tire great- 
est part of it by dying in the mean time. In 
several of these schemes, which have lately 
expired, the division to the subscribers has 
been considerably less than the amount of 
their contributions. 
TOOTH. See Anatomy. 
TOPASFELS. See Rocks, primitive. 
TOPAZ. The name topaz has been re- 
st ricted by Mr. Hauy to the stones called by 
mineralogists occidental ruby, topaz, and sap- 
phire ; which, agreeing in their chrystalliza- 
don and most of their properties, were ar- 
