vil CONTENTS. 
thylie Aldehyd, A, W. Hormann, 249.—On Franunhofer’s lines, and on the violet 
rtion of the solar spectrum, ANGSTROM and THALEN, 250.—Carbonylic Sulphid, 
, 251.—Manufacture of sodic carbonate, san eal Allotropie states.of Me- 
tallic Arsenic: Metallie Cerium,’ WOnLen » Bh.-Rchicate teat foralkalies, BoEtTTGER : 
.—On Glycerin and its derivatives, Burr , 256. —The organic dase, Neurine, (a. ) 
its discovery, L1EBREICH: (b.) Its atiuil constitution; BAEYER .—(e.) Neu- 
rine and choline me DypxKowsky, 259.—(d.) Its rational formula established, 
BaEYER, 260.—(e.) Identity of neurine and sinkaline, A. CLavsand C. Kerse: 
(£) Synthesis of neurine, Wurtz, 261,—Hydrocarbons ‘of the Pennsylvania Petro- 
leum, by C. M. WaRREN, 262. 
neralogy and Geology.—The Carboniferous age of a portion of the Gold-bearing 
Rocks of California, WiLL1AM P. BLAKE, 264.—Memoirs presented to the Califor- 
nia Academy of Sciences, vol. i, part II. ‘“ Principles of the Natural System of 
hints: o Rocks, by F. BARON RICHTHOFER, 2 267. Report on the Geol ology of Ne- 
olcaniques 
pie eles Aleutiennes, de la Peninsule d’Aljaska, et de la Cote F. 0. d’ Amérique, 
par M. ALEX? : Not Tremblements de Terre en 1863 avec sup- 
pidments pour les ambos enierieures de 1843 4 1862, par M. ALuxis Perrey, 268. 
Botany and Zoology.—Miocene Flora of the Polar Regions : Les Fleurs de Pleine Te re 
Qeme edition, 1866. Atlas des Fleurs de Pleine Terre, ete. ; par Vilm “ese 
& Cie. Paris, 1867,269.—The great Dragon Tree of Orotava, 270.—Geological and 
Natural History Survey of abe Aigete ae. etc., by Rev. M. A. Pit og Genera 
tarum, by BentHaM and Hi : Hustrations of the Genus “etic by Fran- 
cis Boort, 271.—Botani eaaktinctlogy for 1867, concluded, 272.—Memoirs abetnag 
ted to the California sue of Sciences, etc., vol. i, part I, by 9 pba : 
A Botanical Semi-centennial, 273. 
Miscellaneous Scientific Intelligence.—Die trockene Distillation des Holzes und Verar- 
beitung der durch dieselbe erhaltenen Rohproducte auf feinere, 274.—Reclama- 
cene Flora of North Greenland, by Professor OswaLp pean 281. Obituary.— 
Christian Gottlieb Ferdinand Engel, 282.—Sir David Brewster, 284. 
Miscellaneous Bibliography.—The American Ephemeris and Nautical Almanac for 
the year 1869, 284.—Sound ; A course of eight lectures, &e., by Jonn Tryp 
286.—Guyot’s Pe oe Text Books, 287.—A Journey in Brazil, by Professor 
and Mrs. Louis Acassiz 
NUMBER CXXXyV. 
Page. 
Art. XXX. On the Musical Ratios, and our Pleasure in 
‘Harmonious Sounds; by Henry Wis FOG EM. on oe 289 
‘XXXL On the measurement of wareinge by the method 
of comparison; by Wotcorr Gisss 298 
cage On the Comparative Efficiency of different forms 
ee by Hpwanp C. Pagenane, EE RE 301 
