522 Professor Peraj F. Franldand [Feb. 19, 



of destroying micro-organisms, and which we call antiseptics, whilst 

 similarly the process is stopped by heat and other influences, which 

 are known to be fatal to life in general. 



These results of Schloesing and Miintz were confirmed and greatly 

 extended in this country by Mr. Warington and Dr. Munro, but 

 although the vital nature of the process was fully established, little 

 practical advance was until recently made in the identification or 

 isolation of the particular bacteria responsible for this remarkable 

 and invaluable transformation. 



In 1886, however, a very important step was made by Dr. Munro, 

 who showed that this j^rocess of nitrification could take place in 

 solutions practically destitute of organic matter, or, in other words, 

 that the vital activity of the bacteria of nitrification could be main- 

 tained without nutriment of an organic nature. 



In 1885, I had myself already established the fact that some 

 micro-organisms can actually undergo enormous multiplication in 

 ordinary distilled water : — 



Multiplication of Micko-organisms in Distilled Water.* 



Hours after Introduction Number of Micro-organisms 



of Micro-organisms. found in 1 c.c. of Water. 



1,073 



6 6,028 



24 7,262 



48 48,100 



In taking up the subject of nitrification in conjunction with my 

 wife in the autumn of 1886, I determined to avail myself of this 

 remarkable property of the nitrifying organisms to grow in the 

 absence of organic matter, thinking that in this way it would be 

 possible to achieve a separation of the nitrifying organisms from 

 other forms which can only grow if organic food materials are sup- 

 plied to them. 



Proceeding on these lines, we have carried on the process of 

 nitrification over a period of upwards of four years without the 

 nitrifying organisms being supplied with any organic food materials 

 whatsoever : — 



Composition of Solution Employed for Nitrification. 



Ammonium chloride '5 grm.\ 



Potassium phosphate '1 m I t i nnn e 



Magnesium sulphate -02,, ," ,,"^\ 



Calcium chloride -01,, distilled water. 



Calcium carbonate 5 • „ J 



In a solution of this composition the process of nitrification was 

 carried on over a period of upwards of four years, as indicated in the 

 following table : — 



* Proc. Eoy. Soc, 1885. 



