PREVENTIVE MEASURES 
201 
Dr. H. W. Wiley, the Chief Chemist of the U. S. 
Department of Agriculture, was asked for an opinion 
regarding the effect upon the manurial value of manure 
treated by the substances experimented with under Pro¬ 
fessor Forbes’s direction. He replied, “The materials 
which you mention would affect the agricultural value 
of manure in three ways: Alkalies would drive off am¬ 
monia, and if in not too large quantities, would hasten 
fermentation. Lime salts and iron sulphate would 
tend to render the phosphates unavailable. All of these 
materials mentioned, with the possible exception of 
salt, would, if used in sufficient quantity, kill the bac¬ 
teria of the manure and thus reduce its value, as un¬ 
doubtedly the value of stable manure is largely due to 
the great number of very active bacteria which it con¬ 
tains. I cannot inform you in what quantities these 
various materials would be required to seriously re¬ 
duce the bacterial content of manure, but it would seem 
that, if used in sufficient quantity to kill larvae, they 
would have a decided effect on the bacterial life of the 
manure.” 
Removal of Manure and Receptacles for Its 
Temporary Storage 
The average time elapsing between the laying of the 
eggs and the issuing of the adult flies, as we have seen, 
is, in midsummer in the climate of Washington, about 
ten days. In warmer regions, and with plenty of mois¬ 
ture, it may be as short as eight days. Therefore it is 
by all means advisable to have manure accumulations 
