LEM 
theran religion ; but he never went to ser- 
mons ; and when in his last sickness his fa- 
vourite servant desired to send for a minis- 
ter, he would not permit it, saying he had 
no occasion for one. He was never mar- 
ried, nor ever attempted it but once, when 
he was about fifty year’s old ; and the lady de- 
siring time to consider of it, gave him time 
to do the same : he used to say, “ that mar- 
riage was a good thing ; but a wise man 
ought to consider of it all his life.” 
Leibnitz was author of a great multitude 
of writings, several of which were publish- 
ed separately, and many others in the me- 
moirs of different academies. He invented 
a binary arithmetic, and many other inge- 
nious matters. His claim to the invention 
of fluxions was the subject of much contro- 
versy, for which the authors of the time 
may be consulted. 
Hanschius collected with great care 
every thing which Leibnitz had said in dif- 
ferent passages of his works on the princi- 
ples of philosophy ; and formed of them a 
complete system, under the title of “ G. G. 
Leibnitzii Principia Philosophic more geo- 
metrico demonstrata, «Scc.” 1728, in 4to. 
There came out a collection of our Author’s 
letters in 1734 and 1735, entitled “ Episto- 
1® ad diversos theologici, juridici, mediciy 
philosophici, niathematici, historici, et 
philologici augmentile MSS. anctores : cum 
annotationibus suis prjmum divulgavit Chris- 
tian Cortholtus.” But all his works were 
collected and distributed into classes by 
M. Dutens, and published at Geneva in six 
large volumes 4to., in 1768, intitled “ Go- 
thofredi Gulielmi Leibnitzii Opera Omnia, 
&c.” 
LEMMA, in mathematics, denotes a pre- 
vious proposition, laid down in order to 
clear the way for some following demonstra- 
tion ; and prefixed either to theorems, in 
order to render their demonstration less per- 
plexed and intricate, or to problems, to 
make their resolution more easy and short. 
Thus, to prove a pyramid one-third of a 
prism, or parellelopiped, of the same base 
and height with it, the demonstration where- 
of, in the ordinary way, is difficult and 
troublesome, tliis lemma may be premised, 
which is proved in the rules of progression, 
that the sum of the series of tte squares, 
in numbers in arithmetical progression, be- 
ginning from 0, and going on 1, 4, 9, 16, 
25, 36, &c., is always subtriple of the sum 
of as many terms, each equal to the great- 
est ; or is always one-third of the greatest 
term multiplied by the number of terms. 
LEM 
Thus, to find the inflection of a curve line, 
this lemma is first premised, that a tangent 
may be drawn to the given curve in a given 
point. 
LEMNA, in botany, a genus of the Mo- 
noecia Diandria class and order. Natural 
order of Miscellane®. Naiades, Jussieu. 
Essential character : male, calyx one- leaf- 
ed-^ corolla none : female, calyx one-leafed ; 
corolla none ; style one ; capsule one-celled. 
There are six species. These plants are 
well known by the name of “ duck’s meat,” 
or “ duck weed.” They are all annuals, 
and are found floating on stagnant water. 
They are natives of most parts of Europe, 
in ditches, ponds, &c. 
LEMNISCIA, in botany, a genus of tlie 
Polyandria Monogynia class and order. Es- 
sential character : calyx five-toothed ; co- 
rolla five-petalled, recurved ; nectary cup- 
shaped, girding the germ ; pericarpium five- 
celled ; seeds solitary. There is but one 
species, viz. L. guianensis. The trunk of 
this tree is about twenty feet in height, and 
one foot in' diameter ; the bark is brown 
and smooth ; the wood is white and com- 
pact ; abundance of twisted branches spread 
in every direction ; leaves alternate, firm, 
and smooth ; flowers at the ends of the 
shoot, very numerous, in large corymbs, on 
a woody peduncle : corolla of a fine coral 
red. Native of Guiana. 
LEMON. See Citrus. 
Lemons, salt of, used to remove ink- 
stains from linen, is the native salt of sorrel, 
the super-oxalate of potash. The effect i» 
produced by the oxalic acid dissolving with 
facility the oxide of iron in the ink, on the 
combination of which with the tannin and 
gallic acid the colour depends ; while, at 
the same time, it can be used without any 
risk of injury to the cloth, on which it hat 
no efifect. See Oxalate. 
LEMONADE, a liquor prepared of wa- 
ter, sugar, and lemon or citron juice. It 
is very cooling and gratefiil. 
LEMUR, the macauco, in natural history, 
a genus of Mammalia, of the order Pri- 
mates. Generic character : in the upper 
jaw four front teeth, the intermediate ones 
remote ; in the lower jaw six, longer, ex- 
tended forwards, compressed, parallel, and 
approximated ; tusks solitary and approxi- 
mated; grinders several, and sometimes 
many, sublobated, the foremost somewhat 
longer and sharper. This genus of ani- 
mals is very similar to that of monkeys in 
the structure of the feet. Some are, desti- 
tute of a tail, and others have extraordinaiy 
