14 



The Weekly Florists' Review. 



Decbubeb 17, 1908. 



STERILIZATION WITH FORMALIN. 



We noticed an article in the EtfviEW 

 of November 19, page 48, under the head 

 of "Soil Sterilization," and would like 

 to know where we can get more informa- 

 tion as to the use of formalin, what it 

 is, where to get it, what it costs, and 

 about the apparatus for making it, etc. 



J. S. & S. 



Your issue of November 19, 1908, con- 

 tains an article on "Soil Sterilization," 

 by B. H. Thome, in which he refers to 

 several methods of soil sterilization, 

 among which is sterilization by means 

 of formalin. Will you kindly give us 

 some further information concerning its 

 use? We have sterilized soil with steam, 

 but have never tried any other way. 



H. F. C. 



Neither of these two correspondents 

 seems to have read the first part of the 

 article on sterilization, which appeared 

 on page 76 of the Review of November 

 12, and which contained much of the in- 

 forma^tion for which they are now ask- 

 ing. If they will now read the first in- 

 stallment of the article, they will there 

 find specific directions about the various 

 steps in the use of formaldehyde, or for- 

 malin, from the preparation of the soil 

 to the end of the process. The machine 

 called a "mixer" is there described at 

 some length,* and other methods of using 

 the formalin are also mentioned, such 

 as applying it with a barrel force pump 

 and hose, or putting it into the water 

 tanks, in greenhouses where tanks are 

 used. It is there stated that "the for- 

 malin 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 con- 

 nected 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." 



As an aid to a clearer understanding 

 of the mixer, a diagram of it is here- 

 with given. The numbers on the dia- 

 gram are explained as follows: 



1 — Inlet valve from waterworks. 



2 — Hose-bib for drawing off lower tank. 



3 — Outlet valve from tank Into waterworks 

 system. 



4 — Glass gauge to show when water gets too 

 bigb In lower tank. , 



5— Air valve. / 



6 — Valve between the tanksX 



7 — Pressure gauge. ^^■ 



8 — Filling pipe, for fornlalln tank. 



9 — Glass gauge for formalin tank. 

 10 — Draw-off valve for formalin tank. 

 11— Needle valve to ceg!^J«Ie flow of formalin. 

 12— Glass gauge to shoW 'Whether formalin is 



flowing properly. 

 13 — Air valve used in filling formalin tank. 



To regulate the mixer, first run 

 through fifty gallons of water and time 

 it; then take off the glass gauge at 12 

 and regulate the needle valve so that two 

 pounds of formalin will run through in 

 the same time as the fifty gallons of 

 water. A long" pointer and dial should 

 be placed on the handle of the needle 

 valve, and when the valve has been reg- 

 ulated for the right quantity it should 

 be marked on the diaL 



To operate 'the mixer, first open the 

 air-cock at 13; fill the formalin tank 

 half or two-thirds full of formalin. 

 Close the valves at 11 and 3, and run 

 water in to put on the pressure. When 

 the pressure is all on, close the valve at 

 6, run out the water at 2 and open the 

 valve at 5 to let air into the lower tank. 

 After the water is out, close the valves 

 at 2 and 5. The mixer is now ready to 

 use by opening valves 1, 12, 3 and 6 in 



Apparatus U>ed for Sterilizine With Formalin. 



the order named. With this apparatus 

 one man can do the same amount of 

 work that six can do with a barrel and. 

 pump. 



Formalin, or formaldehyde, is a gas 

 that is forced into water under pressure. 

 When it is spread over a large surface 

 it evaporates and in a few days no trace 

 of it is left, and for this reason it is 

 excellent for sterilizing soil. It pro- 

 duces no change in the soil and leaves no 

 residue, and it will kill any live germs 

 or fungi with which it comes in contact, 

 either in the mixture or as a gas. It 

 cannot be used in the gaseous form in 

 the greenhouse, if any plants are in it, 

 as it kills them the same as burning sul- 

 phur. There is no danger, however, in 

 using it in the mixture on empty beds in 

 close proximity to other plants, as the 

 gas does not evaporate fast enough to do 

 any harm. 



Formalin is manufactured by the 

 Perth Amboy Chemical Co., Perth Am- 

 boy, N. J. Strong & Cobb and, I be- 

 lieve, Harshaw, Fuller, Goodwin & Co., 

 both of Cleveland, O., handle it in whole- 

 sale lots. 



As to its cost, I cannot say at present, 

 but I have paid from 9 cents to 15 cents 

 per pound, depending on the quantity. 



B. H. Thorne. 



MEALY BUG. 



I have a greenhouse in a small town. 

 My flowers are troubled with a peculiar 

 disease, or bug, or louse. I send you 

 a sample of them. They will thrive on 

 any plant. Fumigating does not kill 

 them. I have tried several things. Catt 

 you tell me what they are and what 

 I should do to get rid of them? 



T. W. S. 



The specimens received were mealy 

 bugs, one of the worst pests the florist 

 has to combat, but which is not often 

 allowed to overrun everything, as in your 

 case. If you had used a strong pressure 

 of water, driven through a spray nozzle, 

 once or twice a week, many of the bug» 

 would have been destroyed. Ordinary 

 fumigation has no effect on these bugs, 

 but if you will use hydrocyanic acid gas,, 

 as recommended frequently in the col- 

 umns of the Beview, you can clear them 

 out effectually. Once you have gotten 

 them clean, syringe your plants occasion- 

 ally, using a good force of water, to- 

 keep them in check. It will probably 

 pay you to throw away any coleus or 

 other bedding plants which are badly 

 infested. C. W. 



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