New YorK AGRICULTURAL EXPERIMENT STATION. 345 
In the field experiments, the preparations of the oil emulsion 
and miscible oil caused no apparent harm to any of the trees, even 
when the roots were immersed. The emulsions containing 15 per 
ct. and 20 per ct. of kerosene, or miscible oil diluted with 10 and 15 
parts of water, were more efficient as dips on the San José scale 
than the sulphur wash. In laboratory tests conducted later, trees 
were frequently severely injured by the immersion of their roots 
in emulsions containing 20 per ct. of kerosene. Fumigation with 
hydrocyanic acid gas completely destroyed the scales and the treat- 
ment was not harmful to the trees. 
The results of these experiments indicate that dipping of nursery 
trees in the standard lime-sulphur wash for the purpose of destroy- 
ing the San José scale is a doubtful practice. Nurserymen are 
advised to continue the use of fumigation with hydrocyanic acid 
gas, which is the more efficient means of freeing dug nursery stock 
of this pest. 
ENGDRODWC LION: 
With the introduction of the San José scale as a nursery and 
orchard pest, some system of official supervision of nurseries, which 
had in view control of this insect, became imperative. To this end, 
nursery inspection laws, designed principally to prevent the dis- 
tribution of the scale by the trade and to protect innocent pur- 
chasers, were enacted in many states. The official inspection and 
certification of nurseries that followed, and the growing practice of 
intending purchasers of buying only of responsible firms, have 
awakened nurserymen generally to the necessity of affording suit- 
able protection to their plants and of selling only clean and reliable 
stock. ‘To meet the demands of the trade for protection against 
the scale, fumigation of nursery stock before shipment with 
hydrocyanic acid gas was put into practice with the passage of the 
inspection laws, and has been generally recognized as the most 
efficient method for the general treatment of the common injurious 
insects of dug nursery.trees. 
DIPPING FOR THE TREATMENT OF NURSERY STOCK. 
Within recent years, interest in the dipping of nursery stock in 
contact sprays has been revived as a means of insect destruction as 
an alternative treatment for fumigation as commonly practiced. 
The mixture generally suggested for the purposes of a dip is the 
lime-sulphur wash, because of its efficiency as a spraying mixture 
