Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-05-12

Of space nature is making them Of poorer
ma terial in every generation. So these
third molars." as dentists term them, be-
gin to decay usually, and have to be filled
or pulled as soon as they appear. Another
thing worth mentioning is the remedy
adopted for a cleft palate which renders
articulate speech impossible, being an open
ing in the roof of the mouth. In the adult
it is incurable by surgery. The dentist SUBJ
stitutes fo- the missing soft palate a plate
with a piece of soft thin rubber attached.
which enables the patient to talk.
1t may be said with approximate correct
ness that one person In every three or four
loses his or her teeth sooner or later by a
disease which attacks the gums. Tartar is
deposited along the edges of the gums
which are gradually forced back until the
trouble attacks the sockets. The first OBJ
servable symptom is tendency of the
gums to bleed when the teeth are brushed
though 1T must not be supposed that such
bleeding necessarily indicates the COM
plant referred to. At length Inflammation
supervenes. and the teeth, though perhaps
perfectly sound, drop out. They become so
loose that the victim sneezes them out
Until within the last few years no remedy
for this trouble was known. Human skulls
thousands of years old exhibit traces of the
disease. But skillful dental surgeons now
treat it successfully, when taken in the
early stages, by keeping the irritating tar
tar scraped away, and by inducing healthy
action in the gums with preparations Of
carbolic acid, iodine, etc.
The Making of Teeth.
1nasmuch- as real teeth so easily lost,
1t is a comfort to know that artificial ones
cost only fifteen to eighteen cents each at
the manufacturers. One maker in New
York sells 100000 teeth every year. They
are porcelain, composed chiefly of kaolin.
The enamel is put on with metallic oxides
the process being so delicate that no two
teeth are exactly alike in coloring After
being finished, thousands Of them are taken
together and matched in shades There are
nIty dlnerent shades, corresponding to
variations IN the coloring of natural teeth.
Defects are often made in false teeth, SO
as TO render them more deceptive to the
eye The best plates are of rubber. Cellu-
loio Is the prettiest material for the pur-
pose. out II does not resist the acids of the
mouth. Aluminium has the advantage of
nghtness, but 1t is affected by vinegar and
SAT- producing salts Of aluminium, which
are injurious.
A tooth is a living structure. Inside of
each tooth is a cavity filled with pulp
which gives 1t life. Nerves and blood YES
sels connect this pulp with the general
system and circulation of the BODY From
the pulp pass into the ivory of the tooth
an immense number of little tubes con-
tanning threads of soft bone The ivory
surrounding pulp is covered over by a sur
race or enamel. Both ivory and enamel are
harder than any other bones. because thev
contain a greater quantity of bone earth
An ordinary bone of a man contains less
than ~ per cent of bone earth, while enam-
Ell is more than 80 per cent of bone earth.
Hence 1t is the hardest of ali materials ~
organic origin.
Enamel on the tops of the teeth is one
stH'eehth OF an inch thick. 1t consists
OF little six-sided prisms placed side nv
side and held together by an exouisiteIy
me cement. This structure forms an ad-
m'rable defense against decay, which. once
having reached the interior ivory. makes
havoc in that relatively soft bone The
pulp OF the tooth becomes diseased, and
toothache follows. Tartar is a secretion
made by three glands in the mouth. AS
put Iorth by these glands. 1t is full of
small living organisms, which assimilate
meter In the saliva and deposit II on the
teeth In the shape Of phosphate Of lime.
Use of Teeth.
mammal usually has several kinds of
teeth. The incisors are to catch and min
little things, as monkeys kill fieas. The
molars are for grinding. the premolars for
cutting up food and the CANNES for lighting
The tusks Of the elephant are the upper
incisors OF that animal. The lance of the
narwhal Is its left upper canine The other
canine is ordinarily aborted. but occasion
ally both are developed, and the freak mar
Whal Is equipped with two lances The
narwhaFs lance is a solid spear of ivory
ten or twelve feet long. Only the male has
II ne can drive 1t through the side Of a
ship. The most elaborate dental apparatus
known Is that of the sea urchin, whose
jaws are composed of forty pieces The
biggest teeth known are those of the mas
todon.
Nitrous-oxide or Laughing gas" most
commonly used as an anaesthetic in den
tistry, Is made from nitrate of ammonia
This nitrate is a salt obtained by boiling
ammonia in nitric acid. The manufacture
buys 1t In granulated shape and boils IL
The gas given off is passed through water
and. being thus purified, becomes the laugh
ing gas of commerce. Makers of dental
supplies put up nitrous oxide in cylinders
Tor dentists under pressure Of 80 pounds
TO the square inch, so that small recepta-
Gle will hold large supply. But the stun
soon detertorates and becomes unwhole-
some. 1t ought always to be used very
fresh. The effects produced by IL vary very
much with the physical idiosyncra sizes Of
people who use IL. Nervous persons under
and to have frightful dreams at the same
time.
After all other materials that go to make
up an animal have turned to dust or have
been transformed into other shapes the
teeth are likely to remain sound and whole
as ever. Thus 1t happens that the teeth
OF numerous species OF creatures long ago
extinct have been preserved to this day in
perfect condition for the instruction of
mankind. Most remarkable among these
perhaps, are the teeth of gigantic sharks
some of them doubtless nearly 100 feet long
which are turned up in great numbers by
the pillow along the shores of the Potomac
and elsewhere. Such sharks teeth To-
gether with the extremely hard ear bones
of whales, have been fetched up in ouanti-
ties with dredges from the bottom of the
deep seas RENE BACHE.