616 
INDEX. 
pared and previously darkened by the action of solar light, 35. VI. Of the analysis of the 
chemical rays of the spectrum by absorbent media, 37. VII. Of the exalting and depressing 
power exercised by certain media, under peculiar circumstances of exposure to solar light, 
on the intensity of its chemical action, 43. VIII. Description of an actinograph, or self-re- 
gistering photometer for meteorological purposes, 46. Note I. On the distribution of the 
calorific rays in the solar spectrum, 51. Note II. On a definite limit of photographic action 
of the blue rays under the influence of an iodic salt, 52. Note III. Acount of a process for 
rendering visible the calorific spectrum by its effect on paper properly prepared, and of some 
further results obtained respecting the distribution of heat therein, 52. 
Hodgkinson (Eaton, Esq.). Experimental researches on the strength of pillars of cast iron and 
other materials, 385. 
Hopkins (William, Esq.). Researches in physical geology. Second series, 193. 
Hunt (Mr. Robert). On the influence of iodine in rendering several argentine compounds, spread 
on paper, sensitive to light, and on a new method of producing, with greater distinctness, 
the photographic image, 325. 
Hydriodic salts, of the whitening power of the several rays of the spectrum under the influence 
of the, on papers variously prepared and previously darkened by the action of solar light, 35. 
I. 
Iodine, on the influence of, in rendering several argentine compounds, spread on paper, sensitive 
to light, and on a new method of producing, with greater distinctness, the photographic image, 
325. 
Iron (cast). Experimental researches on the strength of pillars of, 385 ; power of to resist long- 
continued pressure, 417 ; tensile strength of, 418; compressive strength of, 419; transverse 
strength of, 420 ; relative strength of long pillars of cast iron, wrought iron, steel, and timber, 
430 ; tables of the results of experiments on the strength of cylindrical, rectangular and other 
forms of pillars, 431, 449. 
Iron (wrought). Strength of pillars of, as dependent on their dimensions, 423 ; table of the re- 
sults of experiments on the strength of pillars, 451. 
J. 
Jalap, resin of, 342. 
Johnston (James F. W., Esq.). On the constitution of the resins, Part IV., 341. 
— — . On the constitution of the resins, Part V., 361. 
K. 
Kane (Robert, M.D.). Contributions to the chemical history of archil and litmus, 273. 
Kater (Edward, Esq.). Description of an escapement for an astronomical clock, invented by 
the late Captain Henry Kater, drawn up from his own memorandums, 355. 
Kater (Captain Henry). Description of an escapement for an astronomical clock invented by 
the late, 355. 
L. 
Labdanum, resin of, 344. 
Light. A supplement to a paper entitled “ Remarks on the Theory of the Dispersion of Light, 
as connected with Polarization,” 157. 
