285 
f 
P A L 
io affift Aineas. He was killed by Turnus, the king of 
the Rutuli, after he had made a great daughter of the 
enemy. Virg. JEn. 
PAL'LAS, one of the giants, fon of Tartarus and 
Terra. He was killed by Minerva, who covered herfelf 
with his ikin ; whence, as fome fuppofe, fhe is called 
Pallas. 
PAL'LAS, in mythology. See Minerva, vol. xv. 
PAL'LAS, in aftronomy, a final) planet, difcovered 
a8th March, 1802, by Dr. Olbers, at Bremen ; and fitua- 
red between Mars and Jupiter. It is fo fmall, that it 
does not fubtend an angle large enough to be meafured 
by our beft inftruments. The light refledted by it is at¬ 
tended by more or lefs of a nebulofity, proceeding per¬ 
haps from a copious atmofphere, and extending 468 
miles from the body of the planet. It is remarkable for 
the eccentricity of its orbit, and its inclination to the 
ecliptic, which far exceed that of all the other bodies in 
the fyftem. 
From Dr. HerfchePs obfervations (Phil. Tranf. for 
SS02) we may conclude, that the apparent diameter of 
Pallas is either o"-i7 or o"'i3: its mean diftance from 
the Sun 2 - 8 ; its diftance from the Earth, at the time of 
obfervation, 1 ‘8333 ; and its apparent diameter, at the 
mean diftance of the Earth from the Sun, fubtends an 
angle of o"'3i99 ; fo that its real diameter, if the largeft 
meafure be taken, will be 147 miles; and if the fmalleft, 
refill ting from a more d i ft i n 61 obfervation, be taken, the 
angle under which it would be feen from the Sun will be 
only o"‘2399, and its diameter no more than nof miles. 
The elements of the orbit of Pallas, as others have Hated 
them, are as follow : 
Tropical revolution - - - 4* 7 m u d 
Sidereal revolution, from Mafkelyne’s Table, 1703 d i6 h 48' 
Annual motion - - - i° 18' 11" 
Mean longitude, Jan. 1, 1804 - - 9’ 29 52 38 
Place of afcending node in 1804 - 5 22 28 o 
Eccentricity, the mean diftance being 1 C24630 
Mean diftance from the Sun, that of the? 
Earth being 1 3 2 79 TO 
Mean diftance in Englifti miles - 266,000,000 
Diameter in Englifti miles, according to Herfchel '80 
Ditto, according to Schroeter - 2099 
For farther particulars, as to this and the three other 
newly-difcovered fmall planets, fee the article Planet. 
PAL'LAS, in the Roman hiftory, a freedman of Clau¬ 
dius, celebrated for the power and the riches which he 
obtained. He advifed the emperor his matter to marry 
Agrippina, and to adopt her fon Nero for iiis fuccefl’or. 
It was through him and Agrippina, that the deatli of 
Claudius was battened, and that Nero was raifed to the 
throne. Nero, however, forgot to whom he was indebted 
for it. He difearded Pallas; and fome time after caufed 
him to be put to death, that he might procure his great 
riches. 
PAL'LAS (Peter-Simon, M.D.), an eminent natura- 
lift and traveller, was the fon of Simon Pallas, a Prutfian 
military furgeon, profefibr of Purgery at Berlin, and 
chief furgeon of fhe liofpital in that city. Simon Pallas, 
the father, fignalized himfelf by atreatife on chirurgical 
operations, publifhed in 1763, to which, in 1770, he added 
a fupplemcnt on the difeafes of the bowels; and in that 
year he died, at the age of 76. 
Peter-Simon Pallas, the celebrated naturalift who forms 
the fubjedt of this article, was born at Berlin on the 22d 
of September, 1741. He received the early part of his 
education at home from private tutors, under whom the 
pregrefs he made in his ftudies was truly amazing. Being 
deftined to phyfic, fo early as the fifteenth year of his age 
he entered upon a courfe of ledtures on anatomy, pbyfio- 
logy, botany, medicine, and furgery, under the profeflors 
Meckel, Sprcegel, Gleditfch, Rolof, and his father; and 
applied himfelf with great affiduity to anatomical di'flec- 
tions. He w'as fo apt a fcholar in thefe feveral branches 
Vol. XVIII. No. 1242. 
L A S. 
of fcience, that, in the beginning of 1738, we find him, 
according to the account he gave of himfelf to Mr. 
Coxe, enabled to read a courfe of public ledtures on ana¬ 
tomy. Yet, although he was thus occupied in his pro- 
feftional labours, he ftill found leifure to profecute the 
ftudy of infedts and other claffes of zoology, for which 
he feems very early to have conceived a prediledHon, and 
in which he particularly and eminently excelled. 
In the autumn of the fame year, young Pallas repaired 
to the univerfity of Halle; where he attended the lec¬ 
tures of the celebrated Segneron mathematics and phy- 
fics, and improved his acquaintance with mineralogy ill 
the environs of that city. In the fpring of 1759 * ie re ” 
moved to Gottingen ; and, though prevented by a long 
and dangerous illnefs from profecuting his ftudies with 
his ufual ardour, yet he made numerous experiments on 
poifons and their antidotes, applied himfelf to the dif- 
fedtion of animals, and made repeated obfervations on 
the worms which breed in the inteftines. On this laft 
fubjedl be compofed a very ingenious treatife, under the 
title of “De Infeftis viventibus intra Viventia.” 
In July 1760 he was attradled to the univerfity of Ley¬ 
den by the fame of the celebrated phyficians and natura- 
lifts Albinus, Gaubius, and Mufchenbrseck ; and by 
them he was noticed as a young man of a promifing ge¬ 
nius and indefatigable application. His talents particu¬ 
larly recommended him to the favour of Gaubius, prin¬ 
cipal profeffor and doctor of phyfic in that univerfity. 
In December lie look his dodtor’s degree, and diftin- 
guiftied himfelf by an inaugural difl’ertation, in which he 
defended by new experiments the above-mentioned dil- 
fertation compofed at Gottingen. During his ftay at Ley¬ 
den, his talle for natural hiftory became liis predominant 
paflion ; he employed all the time he could ileal from his 
profeflional ftudies in vifiting the public and private ca¬ 
binets of natural hiftory with which Leyden abounded, 
and was particularly charmed with the colledlion of Gro- 
novius, which he repeatedly examined. 
Having vifited the principal cities of Holland, he di- 
redled his courfe to London, where he arrived in July 
1761. The principal intention of his journey to England 
was to improve his knowledge in medicine and furgery, 
and to infpedt the hofpitals. He was now, however, fo 
much abforbed in his paflion for natural hiftory, that he 
negledted every other purfuit, and gave himfelf totally 
up to this favourite branch of fcience. At this juncture, 
his zeal was fo ardent, that, after having palled the day 
in curioufly examining the various colledtions of natural 
hiftory, and perilling the principal books he could procure 
on that fubjedl, he would frequently employ the greater 
part of the night, and occafionally even whole nights to¬ 
gether, whenever he met with new publication's that 
either awakened his curiofity or interefted his refearches. 
With a view of extending his information in this depart¬ 
ment, he took feveral journeys to the fea-coafts, and par¬ 
ticularly in Sufi'ex. 
Being at length fummoned by liis father to return to 
Berlin, he quitted London with regret, in the latter end 
of April 1762, and repaired to Harwich, in order to em¬ 
bark for Holland. Being there fortunately detained fome 
days by contrary winds, lie embraced that opportunity 
of examining the fea-coaft, and colledting a variety of 
marine productions. On the 13th of May he landed in 
Holland; and, parting through the Hague, Leyden, and 
Amfterdam, he continued his route through the circle of 
Weftphalia, and arrived at Berlin on the 12th of June. 
Previoully to his commencing the pradtice of his profef- 
fion, his father fent him to Hanover, for the purpofe of 
procuring the poll of furgeon in the allied army ; but as, 
upon his arrival in that city, in the month of July, peace 
was on the point of being concluded, he returned, by 
Wolfenlnittle, Brunfwick, and Heimftadt, to Berlin. 
There he parted a year, which he chiefly employed in pre¬ 
paring materials for a “ Fauna Infedtorum Marchica,” 
ora defeription of the infedts in the march of Branden- 
4 D burg.-. 
