The Action of Light on Chlorophyll. 407 



the chlorophyll takes place in the dark in the presence of a dilute solution of 

 permanganate of potash to which a few drops of sulphuric acid have been 

 added. In both cases an aldehyde is produced which can be made evident 

 by means of Schiff's solution. 



11. If a strip of potassium iodide starch paper is exposed to light under 

 coloured filters the paper turns reddish blue under the blue filter, showing 

 the liberation of iodine, but not under the red filter. If, however, the 

 iodised starch paper is first of all tinged with chlorophyll and then exposed 

 to light under the same filters, a strong reaction takes place under the red 

 filter. 



A strip of bleached chlorophyll paper, placed in contact with a strip of 

 damp iodised starch paper in the dark, is also capable of effecting the 

 liberation of iodine, and the starch paper turns blue. 



12. It is suggested in conclusion that the production of sugars and starch 

 in the green leaf may be initiated by the photo-oxidation of chlorophyll and 

 the subsequent polymerisation of the aldehyde thus formed, rather than by 

 the direct photo-synthesis of carbon dioxide and water. 



Intermittent Vision. 

 By A. Mallock, F.E.S. 



(Eeceived November 11, — Eead December 11, 1913.) 



[This paper is published in ' Proceedings,' Series A, vol. 89, No. 612.] 



Studies in Brownian Movement. I. — On the Brownian Movement 

 of the Spores of Bacteria. 

 By John H. Shaxby, B.Sc, and E. Emrys-Eoberts, M.D. 



(Communicated by Principal E. H. Griffiths, F.R.S. Eeceived November 19, 

 1913 —Eead January 29, 1914.) 



[This paper is published in ' Proceedings,' Series A, vol. 89, No. 614.] 



vol. lxxxvii. — B. 



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