No. 4.] AGRICULTURE AND HEALTH. 273 



that no person who is ailing or even slightly ill with any 

 infectious disease should be permitted to have any part in 

 dairy work until such person has entirely recovered and has 

 been pronounced well by the attending physician. If these 

 rules are followed, the milk producer will have less occa- 

 sion to complain of frequent loss in the sale of this most 

 useful article of food. 



A great stir has been made in Europe in recent years, 

 with the object of preventing the importation of certain 

 fruits, the products of American farms. The reasons al- 

 leged, chiefly by the German government, were that poison- 

 ous insecticides were used for the spraying of fruit trees in 

 the United States. Another reason alleged was that zinc 

 had been found in dried fruits. This statement rests upon 

 the fact that apples and peaches and other fruits are often 

 evaporated or dried upon zinc trays, and hence small 

 amounts of metallic zinc are occasionally found in the fruit. 

 The amount, however, is so small and the form in which 

 the zinc is found is such that no harm need be feared from 

 this source. 



The practice of spraying fruit trees in the season of blos- 

 soming and for a few days afterward has become widespread, 

 and demands a moment's notice. The substances used for 

 this purpose are, some of them at least, deadly poisons. 

 Arsenic in the form of Paris green and London purple, with 

 sulphate of copper or blue vitriol, are employed for this })ur- 

 pose, and these make the most efficient means for destroying 

 the various insect pests which attack our fruit trees, currant 

 bushes, potato vines and other plants. 



In the case of fruit trees, like the apple, the principal 

 insect pests are the American tent caterpillar and the canker 

 worm, each of which usually hatches and begins and com- 

 pletes its destructive work between May 10 and June 20. 

 Now, the season of harvest for the great volume of the 

 apple crop is about October first, and probably none which 

 are raised for export are gathered before September first. 

 There is, therefore, a period of from two to three months, 

 in which the average rainfall is about three inches per 

 month, — a quantity amply sufficient to wash away all traces 

 of the spraying substances from the fruit and the leaves. 



