Florida Agricultural Experiment Station


chine. The solution should be constantly agitated while the mixing is tak-
ing place. The lime solution should be kept stirred so that each gallon
will contain the same amount of lime.
 Smaller quantities can be made by dissolving the amount of blue-
stone required in half the amount of water needed. The lime needed
should be slacked and added to the other half of the amount of water
required. The two solutions can be poured simultaneously into a third
vessel, but stir the mixture while pouring the two solutions together.
 Only wooden vessels should be used as bluestone corrodes metals. Be
sure to pour the mixture thru a fine sieve or cheese cloth before putting
it into the sprayer, or the particles will clog the nozzles.
 Bordeaux mixture must be used the same day that it is made, for if
left standing over night it loses its strength. The stock solutions of blue-
stone and lime can be kept indefinitely, but when they are to be used the
water which has been lost by evaporation must be replaced.
 FUMIGATION
 The trucker or gardener will ordinarily use this method of
killing insects only in greenhouses, cold frames and bins where
seeds or other plant products are stored.
 The common fumigants are:
 SODIUM CYANIDE AND AMMONIUM SULPHATE.-See page 201.
 CARBON BISULPHIDE.-See weevils under corn, page 159.
 PARADICHLOROBENZENE.-See weevils under corn, page 159.
 HYDROCYANIC-ACID GAS.-This gas is cheaper than carbon
 bisulphide for fumigating large rooms and buildings and has the
 added advantage of being noninflammable. It is extremely
 poisonous and great care must be exercised not to inhale it. It
 is made in the following way:
 Compute the cubic contents of the room; then close it
 tightly and stuff all cracks with rags, or paste paper over them.
 Get a large earthenware jar and pour into it 3 fluid ounces of
 water for each 75 cubic feet of space. Into this water pour 1
 fluid ounce of commercial sulphuric acid for each 75 cubic feet
 of space. Be sure to pour the acid into the water and not the
 water into the acid; otherwise you will probably break the jar
 by the heat generated and may be severely burned by the sput-
 tering acid. Into this diluted acid drop 1 ounce of potassium
 cyanide for each 75 cubic feet of space. The jar should be so
 large that it is not more than one-third full before the cyanide
 is added, otherwise it is likely to boil over. After dropping
 the cyanide in, leave the room promptly, shutting the door and
 locking it. The gas will begin to form at once. Cyanide is
 one of the most powerful poisons and should be handled with
 extreme care. It is well for the operator to wear rubber gloves
 if the skin has been injured on any part of his hand and the
 hands should be thoroly washed before being permitted to touch
 the lips.