LAM 
try, but also by the kings of Tartary, who 
send him rich presints, and go in pilgrim- 
age to pay him adoration, calling him La- 
ma.congiu, i. e. god, the everlasting father 
of heaven. He is never to be seen but in a 
secret place of his palace, amidst a great 
number of lamps, sitting cross-legged upon 
a cushion, and adorned all over with gold 
and precious stones ; where, at a distance, 
they prostrate themselves before him, it 
not being lawful for any to kiss even his 
feet. He is called the Great Lama, or La- 
ma of Lamas, tliat is, priest of priests ; and, 
to persuade the people that he is immortal, 
tile inferior priests, when he dies, substi- 
tute another in his stead, and so continue 
the cheat from generation to generation. 
These priests persuade the people, that the 
Lama was raised from death many hundred 
years ago, tliat he has lived ever since, and 
will continue to live for ever. 
LAMB. See Ovis. 
LAMINAE, the thin plates of which any 
thing consists : hence the epithet laminated, 
which is applied to those bodies whose tex- 
ture discovers such a disposition as that of 
plates lying over one another. 
LAMIUM, in botany, archangel, a genus 
of the Didynainia Gymnospermia class and 
order. Natural order of Verticillatae. La- 
biate, Jussieu. Essential character: corol- 
la upper lip entire, vaulted; lower, two- 
lobed ; throat with a reflex toothlet on each 
side. There are thirteen species, several 
of which are considered as weeds, rather 
than garden plants. The L, album, white 
archangel, or dead nettle, is common in 
hedges, on banks, and by road-sides ; flow- 
ering in April and May, when it is much re- 
sorted to by bees, for the honey secreted 
in the bottom of the tube, by the gland 
that surrounds the base of the germ. This 
plant has a disagreeable smell when bruis- 
ed. Phalsna Chiysitis, or burnished-brass 
moth feeds on it : Linnseas says, the leaves 
are eaten in Sweden as a pot-herb, in the 
spring ; no cattle, however, seem to- touch 
it ; and, having a strong, creeping, peren- 
nial root, it should be extirpated, which is 
not difficult. 
LAMP, Argand’s, This is a very inge- 
nious contrivance, and the greatest im- 
provement in lamps that has yet been made. 
It is the invention of a citizen of Geneva; 
and the principle on which the superiority 
of the lamp depends is the admission of a 
larger quantity of air to the flame than can 
be done in the common way. This is ac- 
complished by making the wick of a circular 
LAM 
form, by which means a current of air 
rushes through the cylinder on which it is 
placed with great force; and, along with 
that which has access to the outside, excites 
the flame to such a degree, that the smoke 
is entirely consumed. Thus both the light 
and heat are prodigiously increased, at the 
same time that there is very considerable 
saving in the expense of oil, the combustion 
being exceedingly augmented by the quan- 
tity of air admitted to the flame;- and that 
what in common larhps is dissipated in 
smoke is here conyerted into a brilliant 
flame. This lamp is now very much in use ; 
and is applied not only to the ordinary pur- 
poses of illumination, but also to that of a 
lamp furnace for chemical operations, in 
which it is found to exceed every other con- 
trivance yet invented. It consists of two 
parts ; viz. a reservoir fqr the oil, and the 
lamp itself. The reservoir is usually in the 
form of a vase, and has the lamp proceeding 
from its side. The latter consists of an up- 
right metallic tube, about one inch and six- 
tenths in diameter, three inches in length, 
and open at both ends. Within this is ano- 
ther tube, about an inch in diameter, and 
nearly of an equal length ; the space be- 
twixt the two being left clear for the pas- 
sage of the air. The internal tube is closed 
at the bottom, and contains another similar 
tube, about half an inch in diameter, which 
is soldered to the bottom of the second. It 
is perforated throughout, so as to admit a 
current of air to pass through it; and the 
oil is contained in the space betwixt the 
tube and that which surrounds it. A par- 
ticular kind of cotton cloth is used tor the 
wick, the longitudinal threads of which are 
much thicker than the others, and which 
nearly fills the space into which the oil 
flows; and the mechanism of the lamp is 
such, that the wick may be raised or de- 
pressed at pleasure. When the lamp is 
lighted, the flame is in the form of a hollow 
cylinder; and by reason of the strong in- 
flux of air through the heated metallic tube 
becomes extremely bright, the smoke being 
entirely consumed for the reasons already 
mentioned. The heat and light are still 
farther increased, by putting over the whole 
a glass cylinder, nearly of the size of the 
exterior tube. By diminrshing the central 
aperture the heat and light are proportion- 
ably diminished, and the lamp begins to 
smoke. The access of air both to the ex- 
ternal and internal surfaces of the flame is 
indeed so very necessary, that a sensible 
difference is perceived when the hand k 
