684 
on a photometrical method of esti- 
mating the intensity of, 402. 
MacCullagh, Mr., on the polarization 
of light by reflexion, 494. 
Magnus, Prof. G., on the expansive 
force of steam, 218; on the force 
requisite for the production of va- 
pours, 235. 
Metallic wires, on the incandescence 
and fusion of, by electricity, 432. 
Mitscherlich, Prof. E, on the chemi- 
cal reactions produced by bodies 
which act only by contact, 1. 
Mohl, H., on the structure of the ve- 
getable cell, 91. 
Mueller, Prof. J., on the structure and 
characters of the Ganoidei, and on 
the natural classification of fish, 499, 
543. 
Neumann, F. E., on a photometrical 
method of estimating the intensity 
of ordinary and extraordinary rays, 
as also those of reflected light, 402. 
Organic substances, on the behaviour 
of hyponitric acid towards, 415; 
opinions relating to the composition 
of, 661. 
Osmium, on the allotropic states of, 
247. 
Phosphorus, on the allotropic states of, 
244, 
Planets, hypothesis on the formation 
of, 36. 
Plateau, Prof., on the phenomena 
presented by a free liquid mass 
withdrawn from the action of gra- 
vity, 16. 
Pouillet, M., on solar heat, on the ra~ 
diating and absorbing powers of at- 
mospheric air, and on the tempera- 
ture of space, 44. 
Psychrometer, description of the, 644. 
Pulverulent substances, on the ab- 
sorbing power of, 4. 
Pyrheliometer, description of a, 45. 
END OF VOL. IV. 
INDEX. 
Radiation of heat, observations on the, 
44, 
Reflexion, on Fresnel’s formula for 
total, 402. 
Regnault, V., on the elastic forces of 
aqueous vapour, 559; researches on 
hygrometry, 606. 
Riess, P., on the incandescence and 
fusion of metallic wires by electri- 
city, 432. 
Romer, F. A., on the chalk formation 
of Northern Germany, 115. 
Schleiden, M. J., on the formation of 
cells, 97. 
Seebeck, A., on the polarization of 
light by reflexion, 494. 
Selenium, on the allotropic states of, 
244, 
Silicium, on the allotropic states of, 
242. 
Solar heat, observations on, 44. 
Space, on the temperature of, 44. 
Steam, specific heat and elasticity of, 
200; experiments on the expansive 
force of, 218, 559. 
Steam-engine, principles of the theory 
of the, 213, 559. : 
Substitutions, remarks on the theory 
of, 668. 
Sulphur, on the allotropic states of, 244, 
Tartaric acid, action of, upon water 
and other bodies exposed to it in a 
liquid state, 361. 
Trilobites, on the morphology, classi- 
fication and distribution of, 253. 
Vapours, on the heat and elasticity of, 
189, 559; on the force requisite for 
the production of, 235. 
Vegetable cell, on the structure of the, 
91. 
Vogt, Dr. C., on the structure and 
characters of Amia, 552. 
Wartmann, E., on Daltonism or colour 
blindness, 156. 
Yeast, on the nature of, 18. 
PRINTED BY RICHARD AND JOHN E. TAYLOR, 
RED LION COURT, FLEET STREET. 
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