[' 3 2 9 1 
tion of fpirit of nitre, p. 139. On the tranfmiffijon of acids through an hot earthen 
tube, and further obfervations relating to phlogifton, p. 289. 
Problems. If the ages of three perfons be given, to determine, fiotn any table of 
obfervations, the value of the fum payable on the Contingency of the laft perfou’s 
furviving the fecond, provided the life of the fit ft hr all be then extinct, p. 41. 
This problem folved and demonftrated, ibid. 
I. Given the law of attraction of each of the parts of a given line in terms of 
their diftance from a given point; to find the attraction of the whole line on 
the point, p, 186. 
II. III. Given the attraction of each of the parts cf a given fur face in terms of 
their diftance from a given point, and an equation expreiftng the relation 
between an abfcifs and its correfpondent ordinates of the furface; to find the 
attraction of the furface on the given point, p. 187. Alfo, to find the attraction 
of a given folid on a given point, p. 189. 
IV. Given an equation expreiling the relation between two abfciffae and their cor- 
refpondent ordinate of a folid; to find its folid contents contained between two 
values of its firft abfeiffia, p. 194. 
V. Given an equation exprejfing the relation between the two ahfciffae of a folid, and 
the correfpondent ordinates ; to transform the firft abfeiffia into any other, p. 196. 
Prujfian blue generally fuppofed to be a calx of iron fuper- fat u rated with phiegifton, 
though fuppofed by feme to have acquired fomething that is of the nature of an acid, 
p. 298. The quantity of fixed air. that Fruilian blue would yield by mere heat deters 
mined, p„ 299. 
Punukbay a root of pure lime-ftone difeovered here by Mr. Saunders, p. 83. Abun- 
dance of fire- wood in this part of the country, p. 83. The houfes of this country 
are lofty, and the timbers fubftantial, but the inhabitants are unacquainted with the 
ufe of lime, p. S3, 84. State of the thermometer here, p. 84. 
Qx 
Quadrant of altitude, defeription of an improvement in the application of, to a celeftial 
globe, for the refolution of problems dependent on azimuth and altitude, p. 1. 
Quickjil’ver , experiments on the congelation of, p. 199. Experiment proving that 
quickfilver may be frozen not only in England in fummer, but even in the hotteft 
climate, at any feafon of the year, p. 202. Another experiment illuftrating the 
congelation of quickfilver, ibid. Another experiment on the congelation of quick- 
lilver, p. 203. 
Quickfilver , being frozen and broken, afforded a beautiful appearance of flkt plates 
converging towards , a center, p. 204.' Congealed quickfilver bore an exaCV refem- 
blance, both in colour and plated ftruCture, to fujphurated antimony, p. 205. 
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