266 Scientific Intelligence. 



produce any change in chlorid of silver. Where we have the most light, 

 and at two extremities where the light ceases to affect the human eye, 

 and also laterally bands are exhibited which show the same physical con- 

 ditions, and thus it would appear that the circle of light is not the agent 

 producing this peculiar alteration. Regarding, as appears natural, the 

 ordinary prismatic spectrum as the representation actually of two spec- 

 tra consisting of but three colors— red, blue and yellow, which is shown 

 by the reappearance of red light in the blue and of yellow light in the 

 lavender ray, which blue light appears again at the least refrangible 

 end in the extreme red or crimson ray, we have an explanation of the 

 result above mentioned, and the want of chemical action is shown to 

 arise from the operation indeed of the most luminous bands. By ab- 

 sorbent media, as colored glasses and fluids, these results were more 

 fully explained. The most remarkable results have, however, been 

 lately obtained by the use of colored media ; and it has been shown 

 that every luminous ray, independent of color, may be made to protect 

 chlorid of silver from that chemical change which is induced by the 

 direct action of diffused daylight, — the portion upon which those rays 

 fall being actually preserved as a white space, every other part being 

 blackened. It was contended that no hypothesis of interference would 

 explain this result, which more decidedly proved than had hitherto been 

 done the wide difference between the phenomena of light and actinism. 

 The fact that luminous effect — phosphorescence — was produced by the 

 blue rays of the spectrum appears to oppose this view ; but when we 

 find that almost any variety of glass prevents this phenomenon, and 

 that in like manner electricity was interrupted, it appears more rational 

 to refer phosphorescent phenomena to some peculiar electric excitation. 

 The action of the solar rays on the development of vegetable life was 

 then explained, and the following conclusions suggested as the explana- 

 tion of experimental results frequently repeated: — 1. Germination, 

 which will take place in the dark, is quickened by the actinic force, and 

 retarded and often stopped by the luminous power. — 2. Lignifcation. 

 The decomposition of carbonic acid by the plant is due to some excite- 

 ment of luminous power and is stopped by the actinic force. — 3. For- 

 mation of CMorophyle. Due entirely to the luminous rays. — 4. Flower* 

 ingand Fruiting. Dependent upon the action of the thermic or para- 

 thermic rays of the spectrum, as distinguished from both the luminous 

 and actinic forces. — 5. Motion of Plants. Bending to the blue light 

 and receding from the red, proving the excitement of actinic force. 



3. On the direct production of Heat by Magnetism ; by W. R- 

 Grove, Esq., (Proc. Roy. Soc, Athen., No. 1 131.)— The author recites 

 the experiments of Marrian, Beatson, Wertheim and De la Rive on the 

 phenomenon made known some years ago, that soft iron when mag- 

 netized emitted a sound or musical note. He also mentions an experi- 

 ment of his own, where a tube was filled with the liquid in which mag- 

 netic oxyd had been prepared, and surrounded by a coil ; this showed 

 to a spectator looking through it an increase of the transmitted light 

 when the coil was electrized. All these experiments the author con- 

 siders go to prove that whenever magnetization takes place a change 

 is produced in the molecular condition of the substances magnetized ; 

 and it occurred to him that if this be the case a species of molecular 



