vsGpp., HOUSE FLIBS. KF 
and large applications will cause considerable injury. On the other 
hand, certain investigators have shown that small amounts of borax 
have a stimulating effect. The question is, therefore, whether any 
injury to plants will result from the application of manure treated 
at the rate of 1 pound per 16 cubic feet. To answer this point 
numerous tests were carried out, both in the greenhouse and under 
field conditions, using borax-treated manure for fertilizing a number 
of different crops, such as wheat, potatoes, peas, beans, lettuce, and 
others. As far as these experiments have gone they indicate that if 
manure so treated is applied at a rate of not more than 15 tons per 
acre no injury, as a rule, will follow. However, some plants are 
more sensitive to the presence of borax than others, and the effects 
are more noticeable on some soils than on others. All crops have 
not been tested, nor has the cumulative effect cf borax treatment 
been worked out. It is necessary, therefore, to repeat the warning 
issued in connection with a previous bulletin on this subject, that 
great care should be exercised in the application of borax, so that the 
manure will never receive more than 1 pound for every 16 cubic 
feet and that not more than 15 tons of manure so treated should be 
applied to the acre. 
THE BEST SUBSTANCE FOR TREATMENT OF MANURE INTENDED FOR USE AS A 
FERTILIZER. 
In view of the possible injury from the borax treatment as a result 
of carelessness in applying it, or from other unforeseen conditions, it 
is to be recommended that horse manure and other farmyard 
manures which are to be used as fertilizer should be treated with 
hellebore. Borax, on the other hand, is such a good larvicide that 
it can be used with advantage on the ground of soil-floor stables, in 
privies, on refuse piles, and on any accumulations of fermenting 
organic matter which are not to be used for fertilizing purposes. 
Of course there are a number of other insecticides which are 
effective against fly larvae. Potassium cyanid, Paris green, arsenite 
of soda, etc., are effective, but they are hardly to be recommended for 
general use because of their extremely poisonous nature. Others, 
like pyridine, aniline, and nitrobenzene emulsion, are rather too 
expensive when used in amounts necessary to kill the maggots. 
MAGGOT TRAP FOR DESTRUCTION OF FLY LARVZ FROM HORSE MANURE. 
The second method of handling manure is one which does not re- 
quire the application of chemicals. It is based on the fact mentioned 
on page 7 that the larve of the house fly, when about ready to 
pupate, show a very strong tendency to migrate. They leave the spot 
where they have been feeding and crawl about in search of a suitable 
