114 Indian Museum Notes. [Vol. IV. 



on the top of the knapsack. Three moving rods act instead of a 

 brush to feed the material to the grating. 



3. Vermorel'S " £'£'/«z>. "—This sprayer did excellent work, 

 working throughout all experiments without choking or any hitch. 

 Power is applied by means of a side lever. The spray is fine, of 

 considerable force, and can be directed as desired by means of a 

 moveable nozzle. 



4. StrawsOn'S " Notus ." — This sprayer, of a useful size, is 

 specially suited to insecticides containing matter in suspension, as 

 owing to the presence of two moving blades or stirrers the liquid is 

 kept in a continual state of agitation. A series of nozzle caps 

 permit of regulating the fineness of the spray. 



5. StrawsON'S ^^ Improved Antipest.'*-~h well-constructed and 

 finished sprayer. Possesses the advantage that all working parts are 

 exterior to the knapsack containing the insecticide. A side lever 

 works an air-pump. Two tubes connecting the nozzle to the machine, 

 carry the one the insecticide, the other the compressed air. The 

 air acting on the liquid at the point of junction at the nozzle mouth, 

 produces a spray of varying form. The latter is regulated by two 

 stop-cocks, one controlling the flow of liquid, the other the supply of 

 air. The sprayer, owing to the want of means for agitation, is only 

 suited to insecticides in a state of solution. 



6. ChisWICK Co.'S Sprayer-— Gives a large and powerful spray, 

 and can be used for insecticides both in states of solution and sus- 

 pension. Worked by a top lever and handle on the thrust and pull 

 principle. This was found to be much more fatiguing when in 

 continuous use than machines fitted with side levers in which the 

 weight of the arm is utilised in the stroke. 



Experiments in the Treatment of Red Spider {Tetranychus 

 bioculatus). 



The experiments now to be described were commenced on the 

 29th April. This apparently late date of the application of the 

 insecticides was due to two causes. First, Red spider this year came 

 into evidence on the gardens later than usual; secondly, the object 

 of the experiments was not to prove the \alue of sulphur, or pre- 

 parations containing sulphur, in the treatment of Red spider (this 

 being now a generally acknowledged fact, and taken advantage of 

 by a yearly increasing number of gardens), but to make a compara- 

 give trial of several insecticides that have been recommended or 

 suggested. For this reason it was necessary to delay application 



