100 VEGETABLE FORCING 



be as thoroughly done as in ordinary spraying. Be sure to have the 

 outlet at the faucet end from the formalin entrance at S." 



Mr. Thorne also gives in the same report the following 

 description of a formalin mixer, making it possible to 

 apply the solution through the regular water pipes : 



"The formalin mixer is made of two ordinary kitchen range 

 tanks, one above and at one side of the other. The upper one holds 

 the formalin and the lower one is the mixer. The tops of both are 

 connected by a small pipe with a valve in it. This pipe is to equalize 

 the pressure in both tanks by the passage of air back and forth. 



"The formalin tank has a glass water gauge at the bottom to show 

 when the formalin gets too low, and the lower tank a gauge at the 

 top to show when the water gets too high. From the bottom of the 

 formalin tank a K-inch pipe goes down to meet the pipe from the 

 waterworks running into the bottom of the lower tank. Connect- 

 ing the end of the J4~inch pipe with the water-works pipe are a 

 needle valve to regulate the flow of formalin, and another glass 

 gauge to show that the formalin is running properly. 



"The formalin and water are mixed in the lower part of the lower 

 tank by the moving water coming in continuously and the mixture 

 runs out about one-third of the way up back into the water-works 

 system. The apparatus is connected to the regular watering system 

 through a by-pass. 



"In order to get the right proportions of formalin and water, run 

 50 gallons of water through the apparatus and time it, and then 

 regulate the needle valve to run out two pounds in the same time. 

 An air-pump is needed to force air into the upper tank to force 

 back the water in the lower tank when it gets too full. With this 

 apparatus one man can apply the mixture as fast as the water runs." 



It is also important to spray walks, benches, flats and 

 tools with formalin. 



After sterilizing with formalin, planting should be 

 deferred 10 days to two weeks because the plants will be 

 injured if set too soon. 



Cost. So many factors enter into the expense of steril- 

 izing with formalin that it is difficult to give definite cost 

 figures. When a mixer was used, Thorne claimed that 

 the solution and its application cost about two-fifths of a 



