SCIENTIFIC SUMMARY. 
445 
genesis. By W. H. Ballinger, F.R.M.S., and J. Brysdale, M.B. — The 
Angular Aperture of Objectives. By Robert B. Tolies, U.S.A. — 
Remarks on the Confirmation given by Dr. Colonel Woodward to the 
Colour Test.” By Dr. Royston-Pigott, F.R.S., &c., &c. — Remarks 
on Mr. Carruthers’ Views of Prototaxites. By J. W. Dawson, LL.D., 
F.R.S. — On Ancient Water-fleas of the Ostracodous and Phyllopodous 
Tribes (Bivalved Entomostraca). By Professor T. Rupert Jones, 
F.R.S., F.G.S. — The Pathological Relations of the Diphtheritic Mem- 
brane and the Croupous Cast. By Jabez Hogg, Surgeon to the Royal 
Westminster Ophthalmic Hospital, President of the Medical Micro- 
scopical Society of London, &c. — On Organic Bodies in Fire Opal. By 
Henry J. Slack, F.G.S., Sec. R.M.S. — On the High-Power Definition 
of Organic Particles. No. II. By G. W. Royston-Pigott, M.A., M.D., 
F.R.S., &c. — On the Apparent Relation of Nerve to Connective-tissue 
Corpuscles, &c., in the Frog-Tadpole’s Tail. By R. L. Maddox, M.D., 
H.F.R.M.S. — On a New Sub-stage for the Microscope, and on certain 
Appliances for Illumination. By Edwin Smith, M.A. — The ^ Colour 
Test” and Dr. Pigott. By F. H. Wenham, Vice-President R.M.S.— 
Experiments on the Development of Bacteria in Organic Infusions. 
By C. C. Pode, M.B., Demonstrator to the Regius Professor of Medi- 
cine, and E. Ray Lankester, M.A., Fellow and Lecturer of Exeter 
College. 
PHYSICS. 
A Note on the Spectrum of Chlorophyll. — M. Chautard has a note on this 
subject in a late number of the ^^Comptes Rendus.” After specifying the 
changes produced in chlorophyll by light, he makes reference to the persist- 
ence of green matter in certain plants late in the autumn season; he 
considers this due to the presence of fatty and resinous matters. He finds 
that a solution of chlorophyll in fixed oils (oil of belladonna, e.g.) is not 
sensibly altered after several days’ exposure in full sunlight. The most 
luminous spectral rays are the most active in changing chlorophyll solution ; 
and rays which have already traversed a layer of chlorophyll have no effect 
on a second layer so long as the first is not discoloured. In this experiment 
he used vessels with two or more compartments. Heat modifies chlorophyll, 
but does not readily destroy it at temperatures under 100°. Above 100° 
the chlorophyll undergoes various alterations, according to its degree of 
dryness and the nature of the solvent. Dried chlorophyll is completely dis- 
organised at a temperature about 200° ; whereas, solutions of it in essential 
oils only undergo a slow, gradual change at this temperature, and may even 
resist 225° or 250° for several hours. 
Galvanic Reduction of Iron under the Influence of a powerful Electro-magnetic 
Solenoid. — M. Jacobi, of St. Petersburg, covered the interior walls of two 
glass vessels with cylinders of sheet-iron, and placed in these vessels two 
similar rods of wax, coated first with a thin electro deposit of copper, and 
then with plumbago. The vessels were then filled with a solution of sp. 
gr. 1*27, containing 135 parts of ferrous sulphate, and 123 parts of mag- 
