[ ^ 9 ° ] 
P. 
Palfchau. Account of a German boy of that name, with great talents for mufic, p. 201. 
Petrefattion . Account of one, found on the coaft of Eaft Lothian, p. 35. A piece of 
rope that was adjoining to an iron ring, with fand fo concreted round it as to 
retain impreflions of parts of the ring, p. 36. Incruftation formed within three 
years in a fquare wooden pipe, in a coal mine in Somerfetfhire, p. 41. A pro- 
greflive induration of maflfes of fand, and other matter, at the bottom of the ocean, 
on the coaft of this illand, as at the bottom of the Adriatic, p. 37. 
Piles . Theory of a new machine for driving them, p. 120. Advantages of that in- 
vented by Vauloiie, p. 121. Miftakes in Belidor’s theory of Vauloiie’s machine, 
ibid. A new theory of it propofed, p. 122. Ufeful theorems for comparing dif- 
ferent machines, and determining the coft of the works to be raifed, p. 124. Pro- 
blem to determine the depth to which a pile will fink at each ftroke of a given ma- 
chine, ibid. Belidor’s miftakes in the folution of this laft problem, p. 126. Mif- 
takes of a writer in the Stockholm Tranfa&ions concerning it, p. 126. Several 
corollaries ufeful in pra&ice, p. 127. 
Piflol One for making inflammable air, p. 381. Very ftrong one, for firing dephlo- 
gifticated and aether air, p. 410. 
Plants . Their growth in America not to be efiimated by what we fee in our hot- 
houfes, p. 250. 
Plafter , Comparifon of the Paris Montmartre plafter Hone, with feveral felenitical 
fubflances, p. 16. 
Pubis fulminans , a new theory of, p. 404. 
Pyrites . Aflay of gold Pyrites, p. 328. Seldom contains gold, ibid. Has been 
thought to contain gold united firft with iron, and that compound united with ful- 
phur, ibid. Experiments on a piece which turned out to be in its native form, and 
not mineralized, p. 531. 
0 , 
Quartz, How known from other fubflances with a fparry appearance, p. 27, 
K. 
Rain. Account of that fallen at the Grenades^ from 1772 to 1773, p. 217. Regifter 
of, at Lyndon, for 1778, p. 547. 
Pat toon. See Sugar-Cane. 
Rivers, 
