Report on the Bacteriology of Water. 409 



Doubling periods : 



1. 1020 /* = 10.30 A.M. 10.54 A.M. = 24 minutes at 23 '523 '7 C. 



2. 20-40 = 10.54 11.41 = 47- 23 "7 C. 



3. 40-80 = 11.41 12.22 P.M. - 41 23 '7 24 C. 



4. 80 160 = 12.22 P.M. 1.3 =41 24 24 '75 C. 



5. 160320 = 1.3 1.40 = 37 24 '7525 C. 



6. 320640 = 1.40 2.23 = 43 , 25 C. 



Calculated back : 



459229 -5 /* = 1.25 P.M. 2.5 P.M. = 40 minutes at 25 C. 

 229 -5114 -75 = 12.45 1.25 = 40 24 '525 C. 

 114-75 57-5 = 11.59 A.M. 12.45 - 46 23 '75 24-5 C. 

 57-5 288-75,, = 11.19 11.59 A.M. = 40 23 -7 23 -75 C. 

 28-7514-5 ,, = 10.40 11.19 =39 23-7C. 



Normal doubling periods : 



2244 /t = 10.58 A.M. 11.46 A.M. = 48 minutes at 23 -7 C. 

 4488 ,, = 11.46 12.28 P.M. = 42 23 '7 24 C. 

 88176 = 12.28 P.M. 1.8 = 40 2425 C. 

 176352 = 1.8 1.42 = 36 25 C. 

 *352 704 = 1.42 2.32 = 50 25 C. 



On August 6 a broth-drop of spores was started in the Sachs' box 

 at 10.15 A.M. Temperatures ran as follows : 



Temp. 



Time. C. 



10.15 A.M. = 22-0 



10.50 = 24-5 



11.5 = 25-0 



11.30 = 24-9 



11.45 = 24-5 



12.0 noon = 24'5 



2.0 P.M. = 26-0 



2.30 = 26-0 



2.50 = 26-0 



The measurements were now started on a filament 47'25 /t long, 

 and followed till 4.8 P.M. ; the temperature remained at 26 25'75. 

 Doubling periods : 



1. 47-2594-5 /x = 2.50 P.M. 3.20 P.M. = 30 minutes at 2625 -9C. 



2. 94 -5 189 = 3.20 3.58 = 38 25 '925 -75 C. 



Or, calculated back : 



225112 -5 p = 3.30 P.M. 4.8 P.M. = 38 minutes at 25 -925 -75 C. 

 112-5-56-25,, = 2.57 3.30 =33 26 25'9 C. 



Normal doubling period : 



47 -2594 -5 n = 2.50 P.M. 3.20 P.M. = 30 minutes at 2625 '9 C. 



* Partly calculated ; would probably hare been less. 

 VOL. LYII1. 2 F 



