486 



Soils sterilizer : 



A very effective sterilizer is described as follows : — 



A brick chamber 1 8 inches deep consisting ot brick floor with 

 brick walls 9 inches thick, the chamber is open at the top and divided 

 into two compartments by a brick partition, each compartment having 

 a capacity of two tons. Only one compartment is used at a time, so 

 that the other can be filled while the first is being sterilized. 



Steam is supplied from a portable boiler worked at a pressure of 

 25 = 30 lbs , the steam being led to the floor of the chamber through 

 M in. piping. The tube is here joined to a T piece and from the T 

 piece in each of the pits, six pipes are let into a space between the 

 bricks work on the floor. The pipes between the brick work and the 

 floor are covered over with a layer of sand ; they are 8 inches apart, 

 plugged at the ends and perforated along one side with 3/16 inch 

 holes— about 3 inches apart, and have a fall of I inch. A side drain 

 is provided at one side of the chamber to carry off condensed steam 

 this drain is buried in cinders I inch below the surface and has a fall 

 of 2 = 3 inches. 



Steam can be turned into either compartment by means of valve 

 traps as desired. The soil is placed in the chambers and covered, 

 with sacking and steam allowed to pass through the mass till the tem- 

 perature of the top layer is 2I2''F (i. e., boiling point of water). It is 

 then allowed to steam for 30 minutes— making a total period of about 

 2^ hours. 



As soon as the soil is sufficiently cool, it can be used for seed 

 beds. It can be readily seen, that apart from initial expense which is 

 not high, the apparatus is simple, effective and economical and should 

 be of immense value in preparing good soil for seed beds of all kinds. 



The cost of sterilizing 1,000 cubic feet of soil by this method is 

 stated to be only about 8 shillings. The treatment not only improves 

 the soil but kills all larger forms of life present in the soil likely to 

 be injurious to plant life. 



B. J. Eaton, 

 Agricultural Chemist, F. M. S. 

 and 



Acting Director of Agriculture, F. M. S. 



THE CONTROL OF SCALE INSECTS BY FUNGOID 



PARASITES. 



For some years experiments have been carried out chiefly in the 

 West Indies and Florida, on the destruction of scale insects by infect- 

 ing them with certain fungi parasitic on them. 



That these fungi gave a very severe check to the scale insects in 

 a natural otatc wab shown by an observation on orange scale. 



