SITUATION AND SOIL 59 
school children. Some boys^ gave an account of their inter- 
esting work in the following words : 
We wanted to grow a patch of cowpeas. We sent to the laboratory 
and secured a small packet of sterilized cotton fiber upon which nitrogen 
bacteria were growing. We received, besides, two little packages of chem- 
icals. We were told to dissolve one of these in a bucket of water and 
then drop in the cotton containing the- organisms. The next morning 
we mixed in the second chemical. By simple division, the bacteria grew 
so numerous as to make the water milky. This preparation was then 
sprinkled on the seed just before planting. As the roots sprout, the 
bacteria find their way to them. They at once begin taking in and 
storing up the nitrogen in the atmosphere. 
Many, such experiments are recorded.^ A common but 
convincing test is to plant two strips with peas, treating one 
with fertilizer and the other without. To quote one out of 
many actual records, " The inoculated seed in the first row 
did as well without fertilizers of any kind as the uninoculated 
seed did in the second row, loaded as it was with fertilizers 
at the rate of 800 pounds of phosphate.” 
On the principle that a pound saved is a pound gained, no 
careful gardener will underestimate the value of his compost 
heap. A compost heap provides for the saving of every 
scrap of material which can by hook or by crook be turned 
into plant food. And so in the autumn all old stalks and 
withered leaves, in short everything that will in time make 
soil, should be raked into a pile and given a chance to decay. 
To hasten disintegration it is well to dampen it from time, to 
time, covering it over with boards or with a barrel without a 
head, so that it will not look unsightly. In fact, screened with 
vines, this can even be made into an attractive corner. After 
the pile has been decomposing for several months, mix with 
1 In Miss Mailman’s class. Rice School. 
2 United States Department of Agriculture, Bulletin A"o. 214. 
