366 



IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



In this study the purpose was to use a solution of formalin* such 

 as is given to farmers and to use methods comparable so that 

 comparisons could be more easily made. The method used through- 



12 



—WATER 

 --FORMALDEHYDE 



rr 



JO \5 



TIHC IN MINUTE?" 



20 



Fig. 96. Comparative difference in the absorption for wheat placed, in a 

 formalin solution and in distilled water for periods varying from five to 

 thirty minutes. 



out consisted in counting out 100 seeds of a uniform size, placing 

 these in weighed, glass stoppered weighing bottles after which the 

 weight of the seed was determined and finally the seed was again 

 weighed after it had been subjected to the formaldehyde for a cer- 



•The directions for treating wheat to prevent smut as given by Dr. G. 

 M. Reed are as follows: 



The solution used for treating stinking smut of wheat is made by 

 using one pint or one pound of commercial formalin (guaranteed 40 per 

 cent solution of formaldehyde) to forty gallons of water. One gallon of 

 solution is sufficient to treat one bushel of grain. 1 Dipping — take two half 

 barrels or tubs with holes and plugs near bottom. Place one tub on two 

 saw horses and fill two-thirds full with the solution of formaldehyde. Pour 

 slowly into this solution one-half to one bushel of wheat seed, stirring 

 thoroughly for five to ten minutes so that the smut balls, trash, etc., will 

 reach the surface. Skim this material off and drain this solution into the 

 second tub. Pour the seed into a pile on the floor, exchange positions of 

 tubs and repeat the operation. Cover the treated seed with sacks for four 

 to ten hours.. Sow at once or spread the seed out to dry. 



