1823 
is important. Our problem has been to find simple, practical methods 
of freeing soil in considerable quantities from nematodes and some of 
the more common destructive fungi and related organisms. We have had 
the further problem of doing this work in such fashion that the chemi- 
cal, physical, and biological properties of the soil would be disturbed 
a» little as possible. Many of the hew plant introductions brought in 
by the Office of Foreign Seed and Plant Introduction must be grown in 
quarantine. Many others are grown at our field stations for distrib- 
uting to collaborators and others, and in all cases we endeavor to 
free the soil of any enemies that might prove dangerous to other 
sections of the country, While the appliances and methods described 
are designed primarily to meet our own needs, they have been developed 
with the idea of aiding others, especially experiment station workers 
and our collaborators. In the course of our work we have used some of 
the special devices designed for soil sterilization. We have not found 
them entirely satisfactory. Aside from their first cost, which is 
considerable, there are other factors, such as the ease of handling 
the soil, and more important than all, the effects on the soil itself. 
Some of the devices may render the soil practically unfit for the grow- 
ing of plants. They often puddle the soil and may greatly change its 
physical and biological properties. 
It will suffice to describe briefly the appliances, and then by 
means of photographic reproductions accompanied by short specifica- 
tions, anyone with a little mechanical ingenuity should be able to 
make them or have them made. 
1. The Cabinet Method, (PI. 317.} The apparatus used is a 
simple, tight wooden box made on the order of a cabinet. It is de- 
signed for use where low pressure steam is available, such as is used 
in greenhouse or dwelling house heating. The box is filled with 
drawers which slide on wooden cleats screwed or nailed to the inside 
of the box. The size of the box or cabinet must be made to accommo- 
date the number of drawers to be used. Any number of these cabinets 
may be constructed, the number depending on the quantity of soil it 
is desired to treat. The cabinet illustrated in Figure 1 holds ten 
drawers, each drawer having a capacity of one-half bushel of soil. 
Five bushels of soil may, therefore, be heated at one time. We take 
our steam for this cabinet from one of the greenhouse flow pipes . A 
one-inch connection* is made to the flow pipe, to which is attached a 
one-inch globe valve. A nipple and reducer provide an attachment for 
a piece of ordinary three-quarter inch garden hose. After the drawers 
are filled with soil they are placed in the cabinet and the doors are 
closed and securely fastened. The steam is introduced by means of the 
hose through a hole in the bottom of the cabinet. The condensation 
is collected in a pan or it may simply be allowed to leak out at the 
