552 
INDEX. 
T. 
Tabajheer, a fubftance found in the cavity of Indian canes, 
p. 24. 
Tails of Comets, confid of very volatile particles, p. 153. 
Doubts about their ufes, 153, 154. 
Tar [us, wine was made in the diftiid of that City, 
p. 263. 
Tench, more prolific than carp, p. 286. 
Thina. See Sin#. 
Tr anfparency of bodies, occafioned by the minutenefs of 
their pores, p. 60. 
Trituration , very ufeful to promote the folution of Peru- 
vian bark, p. 229. 
Trout , crooked, in a river of Cardiganfhire, p. 204, 205. 
■ Tujks of large animals, brought over from North America, 
p. 465. Are of fine ivory, ibid. Agree with the foffil 
elephants teeth, found in Siberia, 466. And with 
thole of Africa, 468. 
Twinkling of fixed ffars, occafioned by the inequality in the 
denfity of rays, coming from them in fmall portions of 
time, p. 262. 
V. 
Vapours , which efcape in common diftillation, how they 
may be condenfed, p. 518. 
Vegetable acids, their different affinities with alkaline falts, 
P* 5 1 4* Juices, how to be treated, in order to extract 
their acids, 515. 
- Venus , probably furrounded with an atmofphere, p. 240. 
398. Next tranfit recommended to the confideration 
of all aftronomers, 183. 
Vefpafian , a medal of this emperor found, jn what is called 
Pompey’s pillar, p. 441. 
Vesuvius, its eruption in 1766, p. 194, &c. 
Vinegar, its acid,p. 499. 
4 
Underwood, 
