COMPARATIVE GROWTH OF WATER CULTURES IN ^'ARIOUS 



SOLUTIONS. (ABSTRACT.) 



NORMAX W. SCHERER. 



The ]jurpose of the experiments was to determine: 



1. The most favorable sokition. 



2. Growth in the sohitions. (a) untreated, (b) treated with lampblack, 

 (c) treated with quartz. 



3. Relative growth in solutions of one-half, one, two and four liters. 

 Corn used in all the experiments was gathered liv myself on a farm about 



two miles west of this city. The cobs were taken from one stalk and further- 

 more, to reduce the variability, the grains in one row were used for one series 

 of experiments. The three standard solutions of Sachs. Crone, and Knop 

 were used. 

 The result of the above set of experiments was as follows : 



1. It is difficult to say which was the most favoralile solution, but in my 

 estimation the plants growing inTvnop's solution were the best. 



2. Assuming the gro\\i;h in untreated solutions as standard and comparing 

 the other treatments with it, those solutions treatetl with lampblack gave a 

 retarding effect as did those treated with quartz. 



•3. It was found that growth increased with the quantity of solution used, 

 the concentration remaining the same. 



To verify these results experiments were made with large numbers (134) 

 of culture's. The results were strikingly similar but more marked. In the 

 cultures to determine the best solution, Knop's solution was easily the first 

 with vSachs' solution second and Crone's solution third. The plants in Knop's 

 solution were about five and a half feet tall having tassels and ears with silks; 

 some were cross pollinated by hand and yielded a numlier of grains of corn. 



The solutions treated with lampblack gave very striking results. The roots 

 did not get over three inches long and were very much bunchetl. The tips 

 of the roots v,ere coated with a black slime. It was thought that the result 

 was due to impurities of sulphur or creosote in the lamplilack. so I made 

 some lampblack with a Bunsen burner and a revolving flask. The result of 

 the experiments in this case was more marked than before. The seedlings 

 diefl Ijefore they were eight inches high. 



The quartz used was supposed to be pure, but on examination was found 

 to contain many impurities. Through the courtesy of the Wausau Quartz 

 Company, Wausau. Wisconsin, I give the following analysis according to the 

 State Geologist as follows. 



Silica 99. 07^; 



Iron oxide . 17^f 



Alumins . 52^^ 



Hygroscopic water .06^r 



I'ndetermined . . 18^7 



ICO.CO^ 



The roots of the plants gave streaks of iron along the sides of the jars 

 showing the impure iron present. 



Transpiration amounted to cTne quart of solution per liter ])er week. Solu- 

 tions were replenished from a stock solution. 



