Notes on the San Jose: Scale. 167 



bolts. At the top of each large room on the opposite side there is a door 

 3x2j^ feet for ventilating purposes. There is also a flue opening between 

 the rooms as shown in the illustration, which can be uncapped when it is 

 desired to air the house." (See Fig. 7.) 



Johnson estimates that a house the size of the one described is large 

 enough for parties handling a million or more trees annually. 



The advantage of having a double house or room with a partion in it lies 

 in the fact that when there are large quantities of stock to be fumigated, 

 one side or one room can be filled while the treatment, which should con- 

 tinue for at least a half hour, is being applied to the other, thus greatly 

 facilitating the work. 



In using such a house as this, one would proceed in essentially the same 

 manner as described for using a fumigating box. After the doors have been 

 opened, following a fumigation, the house should be allowed to air for at 

 least ten minutes before an attendant attempts to enter. 



Caution. — In handling sulfuric acid and cyanide of potassium, 

 all possible care must be taken. The former will destroy cloth- 

 ing if it comes in contact with it, and wounds caused by it are 

 very painful and slow to heal. The cyanide of potassium is one 

 of the most deadly known poiso7is. After the fumigating box 

 or house is opened after being used, it should be very thoroughly 

 aired before the attendants approach near enough to inhale any 

 of the gas, as serious results will follow if this precaution is not 

 taken. As cyanide of potassium will absorb moisture if exposed 

 to the air, it should be kept in tightly closed jars or cans. 



Co7i elusion. — In the work of Johnson, this method of treating 

 bearing trees has been proved to be of practical importance 

 when properly managed. In such operations, the trees are 

 covered during treatment by tents constructed for the purpose, 

 and where one has a large number of infested trees, it may 

 be more satisfactory, in the end, to have such tents made and 

 apply this treatment rather than to spray. 



Summary. 



I. With the exception of the pure kerosene and the 20 per 

 cent mixture, the first applications of the various insecticides 

 seemed to be mostly ineffective. The poor physical condition of 

 the whale-oil soap solution may account for its not being more 

 satisfactory. 



