152 THE SPIRIT OF THE SOIL 



which the peat is distributed to stables as peat -moss 

 litter, and on arrival is broken up and stored at one 

 end of a large shed. Water-heated pipes pass 

 through half a dozen bays, and into these the peat is 

 thrown when it has been moistened and thoroughly 

 well impregnated with the aerobic bacteria which 

 change the insoluble Humic acid of the peat into 

 the soluble humates required, both as a bacterial 

 and as a plant food. The peat lies in these bays for 

 about ten days, remaining all the time at the tem- 

 perature which is best suited for the development of 

 the bacteria. During the process it tends to settle 

 down. It darkens in colour, but otherwise there is 

 to the unaided senses no sign of any change taking 

 place. Notably the whole process occurs without 

 the development of any smell. Close to the bays 

 the large boiler is situated. It is designed to carry 

 an 8o-pound pressure of steam. The steam from it 

 passes through pipes, and ends in two large water- 

 jacket cauldrons of the type used in melting tallow. 

 It is set free in these cauldrons through holes pierced 

 in the pipes to insure that the steam shall thoroughly 

 saturate the peat. Once this has been fed into the 

 cauldrons steam is applied to them for a period of 

 about an hour, a period that has proved sufficient 

 to insure the death of all the humating organisms. 



From the cauldrons the peat, now sterile and rich 

 in plant foods, is removed to another shed, where it 

 is impregnated with Nitrogen-fixing organisms, 

 Bacillus radicicola and Azotobacter chroococcum. 

 These require only a short time to develop in the 

 fertile sterilized peat, and this is then spread on the 



