240 roXTRlRUTtOXS 10 oil? KNOWLKbaE OF SOIL FERTILITY, V 



of North Sydney, and contained no trade-effluents. Furthermore, 

 no clay was present, so that a deffocculation by the sewage was 

 out of the question. The worms, etc., were picked out, and the 

 sample exposed to the air. It dried slowly, the clots and lumps 

 retaining the moisture for a considerable time. When dry. it 

 was gently broken up and sifted. 



iShells, paper aud wuod lelaiiied by No. 13 sieve 4'5 



(/'oarse sand and shell fragments retained by No.24 sieve 4'6 

 Fine soil 90-9 



A portion uf the soil (-iOg.) was treated in the Soxhlet fat- 

 extraction apparatus with chloroform, and the extract weighed, 

 after which it was saponified and resolved into paraffins and fatty 

 acids. The residual soil was then extracted with alcohol. 

 Following this, the soil was mixed with water, and heated in the 

 autoclave at three atmospheres" pressure for three hours; the 

 supernatant solution was filtered oft", evaporated, and the residual 

 gum dried. The partial analysis of the soil was as follows* — 



Moisture at 98 1-43 



Moisture at 130" U'44 



Chloroform-soluble I'UfS 



Fatty acid.s (CSi 



Paraffins 0"18 



Alcohol soluble 0"69 



Fatty acids 0"56 (partly lost) 



Volatile and organic niatler 7'60 



Crude gum U.S7 



Sand and ash 88 "76 



The amount of the fatty substances is considerable, and con- 

 stitutes 19% of the total organic matter, while the crude gum is 

 9%. One can readily understand how this soil, containing as it 



•As a control upon the first analysis, lUgr. of soil were tieated for three 

 hours with ether iu the Soxhlet apparatus, and, after the ether liad evapo- 

 rated, the portion was extracted, for the same time, with alcohol, and, 

 tiually, with chloroform. 



Ether extract 1-UU% 



Alcohol extract , 1*21% 



Chloroform extract 009% 



2-30% 



