Report on the Bacteriology of Water. 

 Bichromate. 



367 



I now selected a rodlet for measurement : 



Curve 6-t, p. 568. 



Doubling periods : 



24-75 49 -5/i = 2.15 P.M. 3.15 P.M. = 60 minutes at 21 -7520-75 C. 

 49 5 98-0,, = 3.15 4.16 =61 20-75 20 '5 C. 

 9S-0 196-0,, = 4.16 5.15 =59 20'5 19-5 C. 

 196-0 392-0,, = 5.15 6.48 =93 19 '5 18'5 C. 



Reckoned back : 



585-0292-5 



292 -5146 -25 



73-0 36-5 



6.14 P.M. 7.40 P.M. = 86 minutes at 18 -518-0 C. 

 4.45 6.14 =89 20 '018 -5 C. 

 3.51 ,, 4.45 =54 20 '520 -0 C. 







Here, again, we see that the light effect on spores is obvious enough, 

 and that with daylight, which gives no measurable results with 

 growing Blaments at all. We obtain a more vivid impression of the 

 differences of behaviour of these two cultures if we note the following 

 points : 



The water-culture took 101 minutes to grow from 50 fi long to 

 100 ft, double its length at 19'5 19 C., and 120 minutes to grow 

 from 67'5 /t to 135 /* at 20 18 C. ; whereas the bichromate-culture 

 grew from 292'5 /t to 585 /* (i.e., doubled its length) in only 80 

 minutes at 18'5 to 18 C., and only took 89 minutes to grow from 

 146-25 to 292 fi at 20 lb'5. 



