[ 534 ] 
pofiiMe quantity of ether in freezing water, &c. p. 514. Method by which the 
mercury in the thermometer was brought down to 29 degrees below the freezing 
point, ibid. Method of freezing water by the evaporation of ether, p. 515. A 
greater quantity of ether and longer time are required to freeze water in winter than 
infuttimer, p.516. The proportion between the quantity of the ether and of the 
water that may be frozen by it, feems to vary according to the quantity of water, p. 
517, A final 1 apparatus for making ice in hot climates, p. 518. Electrization 
increafes very little the degree of cold produced by the evaporation of ether, p. 518. 
Cork preferable to glafs ftopples for confining ether, ibid. Mr. Winch’s eafy and 
expeditious method of purifying vitriolic ether, p. 519. Inconvenience attending 
that procefs, ibid. The common opinion, that water combines with the pureft part 
of ether, when thofe two fluids are kept together, refuted, p. 520. Experiments 
relating to the expanfion of mercury, ibid. Method of inveftigating the expanfion 
of quickfllver, or its increafe of bulk when rarified by a different degree of heat, 
ibid. Apparatus for that operation, ibid. Method of making the fcale for it, 
p. 52 1. Calculation of the above experiments in decimals, p. 522. The cavity 
of the tubes employed in thefe experiments muft be perfedly uniform throughout, 
p. 523. How to determine the boiling or freezing point on the fcale, p. 524. 
Defcription of a thermometrical barometer, ibid. The determination of the various 
degrees of heat fhewn by boiling water under different prefiures of the atmofphere 
completed by Sir George Shuckburgh, ibid. Probability of conftrudting a thermo- 
meter, with proper apparatus, which, by means of boiling water, might indicate 
the various gravity of the atmofphere, ibid. 
Children . See Bland, Wright • 
Chudnah river. The only fubordinate branch of the Ganges which is at all times 
navigable, p. 92. 
Chymical affinities. The dodlrine of, hath been lately much improved by Mr. Bergman 
of'Upfal, and Mr. Wentzel, p. 7. 
Cocchus Caeca. See Kerr . 
Cold . See Herfchel. 
Cofa , 2 river equal to the Rhine. Variation from its former courfe, p. 97. 
Cpffimbuxar river. See Hoogly. 
Cows head. A remarkable rock, p. 89. 
Crawford^ Dr. Adair, his experiments on the power that animals, when placed in 
certain circumflances, have of producing cold, p. 479. See Fire . That animals 
have, in certain circumflances, a power of keeping themfelves at a lower tempera- 
ture than the furrounding medium, was a difeovery referved for the induftry of the 
prefent age, p. 483. Which was compleated by the experiments of Dr. Fordyce in 
heated rooms, ibid. Various opinions concerning the caufes of the fads eflablifhed 
by thofe experiments, p. 484. Account of thofe experiments, ibid. Experiments 
made on frogs, to difeover with greater certainty the caufes of the refrigeration in 
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