EXAMINATION OF WATER FOR MICRO-ORGANISMS 75 



tlie third day six, on the fourth day four, and on the 

 fifth day two. Taking a concrete example with wort^ 

 suppose No. 1 flask (10 c.c. wort -+- 1 c.c. water) be- 

 comes turbid on the second day, the product is (1 x 8); 

 No. 2 flask (10 c.c. wort + *75 c.c. water) becomes- 

 turbid on the third day, the product is (2x6); No. 3 

 flask (10 c.c. wort + '5 c.c. water) also becomes turbid 

 on the third day, the product is (3 x 6) ; No. 4 flask 

 (10 c.c. wort + -25 c.c. water) becomes turbid on the 

 fourth day, the product is (4 x 4). Then adding these 

 products together, we obtain 



(1 X 8) + (2 X 6) + (3 x 6) + (4 X 4) 

 8 +12 + 18 + 16 =54 



as the numerical expression for the energy with which 

 the particular water is capable of producing growths in 

 wort. 



In the case of beer the above factors are multiplied 



4 X 5 = 6-7 :. 



and in the concrete example given above, if the results 

 had been obtained with beer instead of wort, the nume- 

 rical expression for the energy of growth possessed by 

 the water in respect of beer would be 



(1 X 13-3) + (2 X 10) + (3 X 10) + (4 X 6-7) 



13-3 + 20 + 30 + 26-8 = 90T. 



Numerical Determination of Bacteria in Water 

 (Miquel's Method) 



In a previous chapter (see p. 28) an account is- 

 given of the method of isolating particular micro- 

 organisms from any given material by means of the 

 dilution method. In Miquel's process of water exami- 



