Bordeaux cannot cure internal diseases of the plants. These may be caused by insect borers at the roots, or by some incurable bacterial trouble, and in this case there is nothing you can do but root up the affected plants and destroy them, and then study out how you can prevent its happening again. Sprays for insects usually consist of some form of arsenic or of kerosene emulsion, and occasionally whale-oil soap is used. The most common form of arsenical poison is Paris green, of which about 2000 tons are used annually in this country; this is mixed in the proportion of one-half pound of Paris green to 100 to 150 gallons of water and one-half pound of fresh burnt lime. However, where the insects are very bad, as potato bugs often are, the same amounts of Paris green and lime may be mixed with only 50 gallons of water. Paris green is too caustic to apply stronger than that, except in very rare, specified cases. The Paris green should be mixed with a little water till it is smooth, before it is added to the larger quantity of water. Sometimes it can be sprinkled on, but the only sure results are secured by using a spray, either hand or power. Sometimes Paris green is added to the Bordeaux mixture, and the crops sprayed for insects and diseases at the same time. When this is done, you regard the Bordeaux as water, and add the Paris green in the same proportion as you would add it to water. In this case you need not add the lime, because the lime in the mixture is sufficient. London purple is sometimes used in place of Paris green for the same purposes, and in exactly the same proportion and ways, but it is not so easy to know how strong it is as with Paris green, and it is being used less and less each year. Another preparation is arsenite of soda, which is made of white arsenic, two pounds; carbonate of soda (washing soda) eight pounds; water two gallons. These must be boiled in an iron kettle, which should not be used for any other purpose, for about fifteen minutes, or until the arsenic dissolves. Some water will evaporate during boiling, so, before bottling, add enough to make the full two gallons. This will keep a long time if tightly corked. To make a spraying solution add one-half pint to 25 gallons of water. The quantity given is, therefore, enough to make 8 barrels of 50 gallons each. Unless mixed with Bordeaux, add two pounds of slaked stone lime to each barrel. Be sure to mark your bottle of solution plainly, “POISON.” Arsenate of lead clings to foliage better than any other arsenical poison, and since it does not burn foliage it can be used alone, in the proportion of from one to five pounds to 50 gallons of water. It was first used in 1892 against the gypsy-moth and is annually growing in favor.