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spraying were especially demonstrated to the decided advantage of the 
former in the work against Diaspis lanatus on large, bearing peach 
trees. In the case of trees sprayed with pure kerosene, as noted 
above, all the scales were killed except where they had been protected 
by adhering masses of leaves, which in a number of instances were 
attached to the limbs by insect or spider webs. In such situations the 
scales were not touched by the kerosene and escaped injury. In 
the tent treatment, however, not a living scale could be found, and the 
death of the scales was just as complete under the protections noted as 
where exposed. 
In connevtion with the use of this gas attention may be called to the 
experiments made with “formaldehyde” gas, which was experimented 
with at the suggestion of Dr. EK. A. de Schweinitz. This gas, which 
is a well-known germicide and disinfectant, it was thought might have 
some value as an insecticide. The generation of the gas is not difficult, 
and if it had proven to be of any service against scale insects it would 
have been a valuable addition to known means. It is, however, very 
irritating toethe nose and mucous membranes, and hence would have 
had this objection. Scale-infested shrubs of euonymus were subjected 
to this gas for forty minutes, the gas being generated at the maximum 
quantity for the size of the tent. No results whatever were obtained, 
however, with this gas in the killing of these scales, it apparently 
not having injured them in the least, and its use as an insecticide, 
therefore, is not worth considering in comparison with hydrocyanie 
acid gas. It is, however, stated to have killed young ticks subjected 
to it in laboratory experiments, but not the adults, nor will it kill 
roaches, and even as a germicide it is not effective against all disease 
germs. 
STEAM AND SUPERHEATED WATER. 
The use of steam for destroying insects is not anew method, but has 
recently been extensively experimented with by Dr. S. M. Woodbridge, 
of South Pasadena, and the writer had the pleasure of assisting in a 
practical demonstration of the process and of noting the results of ear- 
lier experiments. The method is very simple and practically identical in 
operation with the gas treatment. The steam is generated in a boiler, 
the one employed carrying 80 pounds, and is introduced into the tent by 
means of a hose. As practiced by Dr. Woodbridge, the hot steam is 
first directed by hand over the trunk and larger limbs; the end of the 
hose is then inserted in a box which has been perforated with inch 
auger holes, the object being to so distribute the steam in the tent as 
to prevent its burning the foliage by striking forcibly in one direction. 
The steam is left on until the temperature, determined by an inclosed 
thermometer, rises to 120° I’. in the tent. Two degrees higher will not 
injure the tenderest growth, but a temperature of 125° and upward 
will kill every blossom, bud, and leaf. 
The time required to bring the tent to the proper temperature varies 
with the day and prevailing winds. A tent covering a tree 10 feet in 
—eS lm. CCS 
