732 CONTRIBUTIONS TO OUR KNOWLEDGE OF SOIL-FERTILITY, vii.-xi., 



At this time, the soil in the garden had been subjected to heavy 

 rains, about 4 inches having fallen in four days, and it was not 

 expected that it would be toxic. A trial bore this out. 

 Experiment vii. 



The loss of toxicity of raw soils, being coincident with the occur- 

 rence of heavy rains, has been already noted.* That it returns 

 again upon the cessation of the rain, and the prevalence of drying 

 winds, is shown in the next experiment, the soil, for which, was 

 taken after a three days' spell of cool, dry S.-W. winds. 

 Experiment viii. 



The return of the toxicity of this specimen of soil, taken 12 days 

 after that of Experiment vii., is evident; and that it is toxic, is 

 shown in test No. 4, which differed from No. 1, in having been 

 shaken only ten times, and immediately filtered. The residual soil 

 from No. 1 was extracted a second time with the same quantity 

 of water, viz., 200 c.c. to 200 grams, and the filtrate was nutritive 

 (No. 5). 



After a dry spell of five days, garden-soil was air-dried in the 

 laboratory for three hours, and was found to contain 3-5 % 

 moisture. It was treated with chloroform overnight, and the dis- 



These Proceedings, 1911, p. 684. 



