614 
INDEX. 
Cells, contribution to the physiology of, 529 ; the doctrine of, 580 ; parent-cell, the germinal ve- 
sicle, 536 ; twin cells, 587 ; reproduction of succeeding cells, 589 ; the rudiinental embryo is 
the nucleus of a cell, 541 ; the chorion formed of cells arising in the oviduct, 545 ; applica- 
tion of facts to the physiology of cells, 546 ; existing views regarding cells, 568 ; chorion 
formed of cells derived from corpuscles of the blood, 600 ; muscular fibre formed of cells 
derived from corpuscles of the blood, 601. 
Chemical action (combined) of rays of different degrees of refrangibility, 23 ; traced much beyond 
the extreme red rays, 28. 81. 
, the source of power in the voltaic pile, 61, 93 ; sufficiency of to produce voltaic 
currents, 117. 
of the rays of the solar spectrum on preparations of silver and other substances, 
both metallic and non-metallic, 1, 
Chemical theory of voltaic electricity , 64 ; comparison of with contact theory, 77 ; adequate to 
explain the phenomena, 61, 93. 
Chlorine, action of, on azolitmine, 321 ; on erythrolitmine, 322. 
Chorion, formed of cells arising in the oviduct, 545 ; diameter of liable to much greater changes 
than that of the zona pellucida, 566 ; formed of cells derived from corpuscles of the blood, 
600. 
Clock, description of an escapement for an astronomical, 335. 
Contact theory of voltaic electricity, 62; comparison of with chemical theory, 77 ; inadequate to 
explain the phenomena, 61, 93 ; improbable nature of the assumed contact force, 124. 
D. 
Daniell (J. Frederic, Esq.). Second letter on the electrolysis of secondary compounds, 209. 
Dunlop (James, Esq.). Table of observations by, of the dip and intensity, made at sea in a 
voyage from England to Australia, 146. 
E. 
Electricity, experimental researches in. Sixteenth series, 61. § 24. On the source of power 
in the voltaic pile, various views of contact and chemical excitement, 62 ; theory of contact 
electromotive force, 64. i. Exciting electrolytes, &c, being conductors of thermo and feeble 
currents, 66. ii. Inactive conducting circles containing a fluid or electrolyte, 68 ; chemical 
and contact theories compared, 77. iii. Active circles excited by solution of sulphuret of 
potassium, &c. 82. 
. Seventeenth series, 93. § 24. On the source of power 
in the voltaic pile (continued), iv. The exciting chemical force affected by temperature, 
93 : cases of one metal and one electrolyte ; one junction being heated, 99 : cases of two 
metals and one electrolyte; one junction being heated, 102. v. The exciting chemical force 
affected by dilution, 104. vi. Differences in the order of the metallic elements of voltaic 
circles, 112. vii. Active voltaic circles and batteries without metallic contact, 114. viii. 
Considerations of the sufficiency of chemical action, 117. ix. Thermo-electric evidence, 122. 
x. Improbable nature of the assumed contact force, 124. Note 127. 
Electricity , voltaic, contact theory of, 62 ; chemical theory of, 64 ; chemical and contact theories 
of, compared, 77. 
Electrolysis of secondary compounds, on the, 209. 
Elemi resin, 366. 
Embryo, the rudimental, is the nucleus of a cell, 541. 
Embryology, researches in. Third series : A contribution to the physiology of cells, 529 ; the 
