EMA Pe Lot 4 
ta beet 
Teeth, See Anarrbichas Luputs 
‘ ‘ So Set yen te 
T. a ih Sea 
eT ‘eqn > 
‘yXe Sear 
Telefeope. See Conftruction of the Heavens. 
Terra Ponderofa, Experiments and Obfervations on, by William Withering, M. D. Pe 
293- Terra ponderofa aérata, its conftituent parts, ibid. Profeffor Bergman’s con- 
jecture concerning it, p. 294. Its more obvious properties, ibid. Experiments on, 
p- 295—297- Conclufions therefrom, p. 298. And obfervations thereon, p- 
298—302. 
%eft Liquor, on a new Method of preparing one to fhew the Prefence of Acids and 
Alkalies in chemical Mixtures; by Mr. James Watt, Engineer, p. 419. Syrop of 
‘violets was formerly the principal tef{ of the point of faturation of mixtures of acids 
and alkalies, ibid. The infufion of tournefol, or of a preparation called litmus fince 
fubftituted in its ftead, ibid. See Litmus, Red Cabbage, Violets. 
Thermometer, See Rain. An Attempt to compare and connect the Thermometer fo 
{trong Fire, defcribedin Vol. LX XII. of the Philofophical TranfaGtions, with the com- 
mon Mercurial ones, by Mr. Jofiah Wedgwood, F. R.S. Potter to Her Majefty, p. 
358. The defign of the experiments recounted in this paper explained, ibid. p. 359. 
The three firft figures of tab. XIX. explained, p. 359. Means employed for obtaining 
an intermediate thermometer, ibid. ‘The fpecies of gage ufed on this occafion ex- 
plained by a reprefentation, p. 360. Caution to be obferved in meafuring the expane 
fion of bodies, p. 361. Effential requifites of the matter proper for the gage, p. 
362- ‘Tobacco-pipe clay and charcoal why preferred in making it, ibid. Method 
of afcertaining a fixed point on the fcale for the divifions to be counted from, p. 363. 
Method of taking the boiling heat of water, p. 364. And that of Mercury, p. 365. 
Fig. 4. explained, ibid. Ditticulty of obtaining the higher degrees of heat, with 
Mr. Wedywood’s thermometer, and his method of performing it, p. 366. Compa- 
rative degrees of the different thermomerers, p. 368. Table of a few principal points 
that have been afcertained, to fhew their mutual relations or proportions to each 
other, p. 370- Scales of the utmott’ limits of heat hitherto attained and meafured, 
ibid. 371. Obfervations on Meff. Lavoifier and De la Place’s method of meafuring 
heat by the quantity of ice which the heated body is capable of liquifying, p. 371- 
Machine for determining the progrefs of liquifying ice, by expofing it to a warmer 
atinofphere, p- 372. Experiment for afcertaining that ice, how cold foever it may 
be, comes up to the freezing point through its whole mafs before it begins to liquify 
on the furface, p. 373. Experiments to afcertaim the abforbing power of ice, ibid. 
374. Apparatus (fig. 6, tab. XV.) for ufing ice in thefe experiments defcribed, p. 
375- Refults of various experiments, p. 376—379- See Hoar-frof. The freezing 
of water is attended with plentiful evaporation in a clofe as well as in an open veffel, 
. p- 3816 


