On Ozone. 409 



be done by making time an element, which would also show the 

 true time of the ozonic daily periods. 



The action of direct light upon the ozonized paper would not seem 

 to exert any great influence on the development of Ozone. By 

 exposing the test-papers under different coloured glasses, and also 

 to the action of polarized light, the following were the results. 

 The expression of 1.00 being for saturation gives the ratio exposed 

 to direct light, .13 ; to polarized light, .64 ; to white light, .57 ; 

 to red, .58 ; to orange, .55 ; to purple, .51 ; to blue, .45 ; and to 

 green, .41. 



The following table of the properties of direct light through col- 

 oured media, is copied for the sake of comparison : — 



Light. Heat. Chemical Action. 



White, 1 1 1 



Red, 4 5 6 



Orange, 6 6 4 



Purple, 3 4 6 



Blue, 4 3 6 



Green, 5 2 3 



The whole sunbeam consisting of luminous rays, heating rays, 

 and chemical or actinic rays, light therefore passing through the 

 above coloured media becomes deprived of one or more of these 

 properties. In submitting the test-papers to these different 

 coloured rays, it is shown that light passing through a green 

 medium prevents the formation of ozone in the proportion .41 to 

 .73. Polarized light would seem to possess the least influence on 

 the development of ozone, — it gives in the proportion of .04 to 

 .73. Next comes white light, then red, orange, purple, blue, and 

 green. Green, it may be remarked, possesses but half the chemi- 

 cal or actinic action of red, purple, and blue. Orange, which 

 possesses the greatest amount of luminous and heat rays, gave 

 Ozone in the proportion of .55 to .73 



The effects of the germination of plants on the amount of Ozone 

 has also formed a subject of investigation here. The test-papers 

 placed among vegetables and flowers, and also on branches of 

 trees, have up to the present time given no decided results; 

 except that during the prevalence of the potatoe rot, the test- 

 papers placed between the rows of the diseased plant, were much 

 more deeply coloured than those placed in the usual situation. 

 But here, at the period of its outbreak, we had rain followed by a 

 hot sun r — an atmosphere peculiarly suited for the development of 



