92 THE SPIRIT OF THE SOIL 



expected. In a later chapter dealing with the results 

 obtained from the use of the peat I shall have to come 

 back to the subject, but in the meantime I will quote 

 from an article contributed by Professor Bottomley 

 to the Illustrated London News a short paragraph 

 describing the influence of the treated peat on the soil 

 as observed in one of many laboratory experiments : 



' When ordinary soil," he wrote, " is mixed with 

 this inoculated peat there is a marked increase in 

 the Nitrogen content of the soil if the temperature 

 be suitable for the growth of the bacteria. A mix- 

 ture of 9 ounces of soil from Rothamsted and i ounce 

 of inoculated peat, incubated at 26 C. (79 F.) for 

 twenty-eight days, gave an increase of 54 milli- 

 grammes of Nitrogen per 100 grammes of soil a 

 gain equivalent to a dressing of 28 cwt. of nitrate of 

 soda per acre, if the increase had been proportional 

 throughout an acre of soil 3 inches deep." 



In the last chapter, it will be remembered, some 

 emphasis was laid on the peculiar colloidal properties 

 of Humic acid, and of its power to adsorb materials 

 from the surrounding medium. In the course of 

 experiments with the peat the apparent paradox 

 has been noticed that the peat enriches the soil in 

 the phosphates available for plant food to a far 

 greater extent than can be explained by the amount 

 of available phosphate in its substance. That it 

 can increase the amount of phosphate actually 

 present is obviously impossible, but that the treated 

 peat itself contains available phosphate and avail- 

 able potash seems clearly settled by such experi- 

 mental evidence as that plants have been grown and 



