1881.] 



Some Experiments on Metallic Reflexion. 



497 



density of the silver being taken as 10*62, that being the value for 

 silver, finally divided by precipitation, given in "Watts' Dictionary," 

 vol. v, p. 277. 



Thickness. 



Film I, removed after 8 minutes, '00004035 millim. 

 „ II, „ „ 11 „ 0-00006848 „ 

 „ HI, „ „ 14 „ 0-00007772 „ 

 „ IV, „ „ 18 „ 0-00008995 „ 



These values for the thickness of the silver films agree fairly well, 

 being of the same order, with those determined by Quincke (" Pogg. 

 Ann.," vol. cxxix, p. 177), who found that similar films varied from 

 0-0000039 millim. to 0'000075 millim. 



f Plate at A, 

 I. i Plate at B. 



L Mean value 



f Plate at A. 

 II. j Plate at B. 



L Mean value 



f Plate at A. 



III. j Plate at B. 

 L Mean value 



f Plate at A. 



IV. \ Plate at B. 

 <• Mean value 



Silver films in air. 



Red light. 



Yello 



P.I. 



P.A. 



P.I. 





o / 





72 55 



30 14 



68 57 



€8 35 



30 02 



68 31 



70 45 



30 08 



68 44 



73 39 



40 16 



70 23 



69 03 



39 39 



69 36 



71 21 



39 57 



69 59 



74 04 



41 25 



70 53 



69 42 



41 10 



70 01 



71 53 



41 17 



70 27 



74 32 



41 21 



71 



69 35 



41 08 



70 37 



72 03 



41 14 



70 48 



light. 



Blue light. 



P.A. 



P.I. 



P.A. 









28 24 



66 30 



31 02 



26 32 



66 29 



30 54 



27 28 



66 30 



30 58 



39 26 



66 56 



40 31 



38 05 



66 43 



38 39 



38 45 



66 49 



39 35 



42 05 



66 40 



40 55 



41 39 



67 17 



40 15 



41 52 



66 58 



40 35 



41 39 



66 36 



40 35 



41 17 



67 19 



41 



41 28 



66 57 



40 47 



Silver films in wa,ter. 



Bed light. Yellow light. Blue light. 





P. 



I. 



P. 



A. 



P. 



I. 



P. 



A. 



P. 



I. 



P. 



A. 





o 











o 





o 





o 





o 





Plate at A. 



69 



53 



29 



32 



67 



07 



33 



25 



61 



39 



33 



44 



Plate at B. 



66 



42 



31 



09 



67 



08 



34 



40 



63 



32 



34 



20 



Mean value 



68 



17 



30 



20 



67 



08 



34 



01 



62 



35 



34 



02 



Plate at A. 



70 



22 



39 



34 



66 



56 



39 



07 



62 



30 



39 



01 



Plate at B. 



65 



41 



39 



05 



66 



47 



38 



44 



62 



43 



39 



14 



Mean value 



68 



01 



39 



19 



66 



51 



38 



55 



62 



36 



39 



07 



Plate at A. 



69 



37 



41 



27 



66 



06 



40 



59 



62 







39 



09 



Plate at B. 



65 



13 



41 



11 



66 



02 



40 



24 



62 



32 



38 



42 



Mean value 



67 



25 



41 



19 



66 



04 



40 



41 



62 



16 



38 



55 



Plate at A. 



70 



34 



41 



02 



66 



41 



41 



01 



62 



44 



39 



12 



Plate at B. 



65 



23 



40 



26 



66 







41 



11 



63 



12 



39 



14 



Mean value 



67 



58 



40 



44 



66 



20 



41 



06 



62 



58 



39 



13 



