39 2 BOTANICAL GAZETTE [may 



nearly insoluble constituents of soil. It has been shown (2) that 

 quartz is of minor importance in the adsorption and retention of 

 hydroxids and various neutral salts; a knowledge of its action for 

 bog water seemed, therefore, of fundamental importance. The 

 quartz used was obtained from the Ceramics Department of the 

 university. To free it from possible impurity it was subjected to a 

 thorough washing. The air-dry quartz sand was first sifted through 

 a sieve having meshes of i mm . Portions of about 25o gm of the sifted 

 material were each placed in a large porcelain dish containing dis- 

 tilled water acidulated with HC1. It was usually the practice to 

 boil the material for twenty minutes. After boiling, the supernatant 

 liquid was decanted and fresh distilled water was added. A similar 

 washing was carried out in aqua regia and later again in dilute KOH. 

 The quartz was then washed repeatedly in boiling distilled water 



The bog water used in these experiments was collected from the 

 same central station on the bog island as described in the earlier 

 paper. The solution is relatively clear, the suspended particles 

 imparting to it a slight tinge of olive green to brown. It is very little 



me 



m • 



Since no experiments had been made thus far to ascertain how 

 much of the toxic property of bog water is removed by a given quantity 

 of an adsorbing agent, series of ten cultures were prepared for this 

 purpose. Seven of the cultures consisted each of 400" of bog wa > 

 to which was added sterilized quartz in quantities equivalent totte 

 following volumes: 25, 50, 75, 100, 125, 150, and 200" respect" p - 

 that is, the quantities were chosen in volumes equal to a de mi 

 fraction of the volume of bog water used. The bog water and . 

 quartz sand were shaken together in glass-stoppered bottles, 

 left standing for several days. When ready for use the liquid I wa- 



decanted and placed in half-liter Mason jars, covered with ac 



, . ,. _ i.p«npctiven 



paper. Three control cultures were added, consisting n»p~ .^ 



of untreated bog water, boiled bog water, and distilled water. ^ 

 wheat seedlings used for these cultures were germinated in sa 

 until 4 to 5 cm high. In later experiments the seedlings were -ger ^ 

 nated in quartz sand. They were then carefully washed in is ^ 

 water and transplanted to the water cultures. Never less 



