ey a 
INDEX TO VOL. IV. 
Assorerion of heat, observations on 
the, 44. 
Actinometer, description of the, 75. 
Agassiz, M., on the structure and 
characters of the Ganoidei, 501. 
Allotropy of elementary bodies, on the, 
240. 
Amia, on the structure and characters 
of, 552. 
Aqua regia, on the nature of, 415. 
Arsenic, on the allotropic states of, 
244. 
Atmosphere, on the periodical varia- 
tions in the pressure of the, 476. 
Atmospheric air, on the radiating and 
absorbing powers of the, 44. 
Attraction, observations on, 5. 
Berzelius, J. J., on the allotropy of 
elementary bodies, 240 ; on the con- 
stitution of organic compounds, 661. 
Biot, M., on the employment of polar- 
ized light in studying various ques- 
tions of chemical mechanics, 292. 
Bodies, elementary, on the allotropy 
of, 240. 
Boracic acid, on its combinations with 
tartaric acid, 374. 
Carbon, on the allotropic states of, 241. 
Catalytic force, on the nature of the, 1. 
Cauchy, M., on the increase in the 
intensity of light by total reflexion, 
402. 
Chalk-formation of Northern 
many, description of the, 115. 
Chemical mechanics, on the employ- 
ment of polarized light in studying 
various questions of, 292. 
types, observations on the, 668. 
Chromium, on the allotropic states of, 
245. 
Colour blindness, observations on, 156. 
Condensing hygrometer, description of 
the, 638. 
Contact, on the chemical reactions 
produced by, 1. 
Daltonism, observations on, 156. 
Dove, Prof. W. H., on the periodical 
variations in the pressure of the at- 
mosphere, 476. 
VOL. IV. PART XVI. 
Ger- 
Dumas’ theory of substitutions and 
chemical types, observationson, 668. 
Electric spark, observations on the na- 
ture of the, 474. 
Electricity, on the incandescence and 
fusion of metallic wires by, 432. 
Emmerich, Dr., on the morphology, 
classification and distribution of tri- 
lobites, 253. 
Fermentation, observations on, 12. 
Fish, on the natural classification of, 
499. 
Flints of the chalk, analysis of some, 
LAs 
Fresnel, M., on total reflexion, 402. 
Ganoidei, on the structure and cha- 
racters of the, 499, 543. 
Gases, on the heat and elasticity of, 
189, 559. 
Gravity, on the phenomena presented 
by a free liquid mass withdrawn 
from the action of, 16. 
Hartig, M., on the structure and 
growth of the vegetable cell, 92. 
Heat, observations on the absorption 
of, 44; on the law of the emission 
of, 56. 
Holtzmann, Prof. C., on the heat and 
elasticity of gases and vapours, and 
on the theory of the steam-engine, 
189. : 
Hydrometers, account of Saussure’s, 
626; descripticn of a new, 688. 
Hygrometry, researches on, 606. 
Hyponitric acid, on the constitution 
of, 415. 
Iridium, on the allotropic states of, 
247. 
Isomerism, on the causes producing, 
240. 
Keene, Dr., on the nature of aqua 
regia, and on the constitution of 
hyponitric acid, 415. 
Kolbe, M., on some conjugate com- 
pounds, 679. 
Light, on the employment of polarized, 
in studying various questions of 
chemical mechanics, 292; on the 
polarization of, by reflexion, 494; 
aC 
