INDEX.- 
Barcmete}\ a portable one defcribed, p. 83. 
Bevis^ Dr. John, his letter containing agronomical ob- 
fervations made at Vienna, p. 150. 
Bloody human, microfcopical obfervations on it, p. 252. 
Brownrigg^ Dr. his experimental enquiry into the mi- 
neral elaftic fpirit, or air, contained in Spa water, 
p. 218. 
C. 
Colehrook^ Mr. Jofiah, his account of the fequel of the 
cafe of Ann James, who had taken the green hemlock, 
p. 271. 
Colours^ the different ones, in natural bodies, arife from 
the different denfity of their component particles, p. ii. 
Experiments on the feveral metallic bodies, what colour 
each produces when feparated from their fulphur, and 
melted and united with glafs, 13. Of their colour 
under other preparations, 28. Conjedure about the 
caufe of the green colour of vegetables, 36. 
Cornet^ (the famous one of 1682) its return predided by 
Dr. Halley at the end of 1758, or beginning of next 
year, p. 295. Reafons of the difficulty in afcertainino- 
the time precifely, ibid. Endeavours of Mr. Clairaut 
on this fubjed, 296. Obfervations on the feveral ap- 
pearances of this comet, from January 21, to June 3, 
1759, and on its comparative pofition to other ftars, 
298, &c. 
Copper, its colour when mixed with glafs, 8cc. p. 20, 
32. ^ 
Cork, Experiments of its fpecifiick buoyancy in different 
waters, p. 95. Of the quantity neceffary to fuftain a 
man in the water, p. 103. 
D. 
Decreafe of Heat, in proportion to the height of fitu- 
ation, p. 126. 
Delaval, 
