222 



YOSHIMURA ; BEHAVIOUR OF 



ioo cc. of a solution of sodium hippurate, containing 0.340 % 

 hippuric acid, were well shaken with 20 grms. of soil from Komaba 

 and filtered off after 24 hours, without washing out the soil. 

 Of the filtrate 50 cc. were evaporated to a small volume and, 

 after addition of some sulphuric acid, shaken with acetic ether. 

 The latter after separation left on evaporating, 0.169 g rm - = 

 0.338 % of hippuric acid. It may, therefore, be concluded that 

 practically none of it was absorbed. 



Two experiments were then made with free hippuric acid 

 on both kinds of soils, but no absorptive power could be noticed 

 to any notable extent. 



In regard to its behaviour towards fungi, I found that dilute 

 solutions of its sodium salt, containing neutral potassium phos- 

 phate and magnesium sulphate, are capable of developing mould 

 fungi and microbes, although this salt must be considered as a 

 poor nourishing material. 



In order to see whether the microbes of the surface soil 

 would be more energetic in decomposing sodium hippurate than 

 those of the subsoil, I took portions of soil at different depths 

 reaching to 140 centimetres, shook them with sterilised water, 

 and infected a sterilised solution, containing 1 % sodium hippu- 

 rate, 0.2 % potassium phosphate and 0.1 % magnesium sulphate. 

 The flasks, plugged with cotton, were allowed to stand from 

 December 29th, 1894, to May 5th, 1895. 



From time to time, a few drops were withdrawn by means 

 of sterilised glass tubes and tested with Nessler's reagent, and it 

 was thus found that, after two months, the solutions infected 

 with the soil from a depth of 50 centimetres, showed moderate 

 reaction, while those infected from greater depths, showed no 

 trace (I) of it. But, later on, and when the temperature had 

 become warmer, increased vegetation of the microbes was noticed 

 in all the solutions, and by the 4th of May, 1895, a strong 

 ammoniacal reaction was obtained in all of them. 



It was interesting to find nitrites absent ; only in one flask 

 was a very slight trace indicated by Griess's reaction. 



(1) The temperature of the room was, until the end of February, generally lower 

 than 5 degrees C. 



