36 EXPEIIDIENT STATION. [Jan. 



year or two trial uf the above luctliod we devised anutber, Avbich 

 has also provetl to be very satisfactory. This consisted in grow- 

 ing plants in boxes, the bottoms of which were covered with 

 wire netting. Over the wire there was spread about an inch of 

 variously treated or untreated libers, as some checks were left 

 in these experiments. The boxes were then filled with soil in 

 which various plants were grown. They were placed over large 

 trays filled with water, a space being left between the bottom of 

 the wire and the surface of the water for the purpose of ob- 

 serving the roots. The object of this test, as before, was to 

 determine what substances would prevent roots from penetrat- 

 ing into the water below. 



Results of Pot Expeeimexts. 



These experiments were started in the spring of 1008 and 

 were conducted along the lines previously described ; that is 

 dift'erently treated fibers were packed into the bottom of com- 

 mon flower pots for the purpose of determining wdiat effect they 

 would have on root penetration. 



About 1 inch of the fiber was packed in -l-inch pots. In 

 some of the pots the fiber was packed rather tightly and in 

 others laid in loosely. On top of the filler were placed 3 or 4 

 inches of soil and clover and grass seed sown ; in some cases 

 willow cuttings and other plants Avere also nsed. Several series 

 of pot experiments were conducted. In all cases the pots were 

 placed in saucers or in galvanized iron trays coutaining about 

 half an inch of water, although the pots were Avatered occasion- 

 ally from the top. 



The substances used in these pot experiments and the treat- 

 ment given are as follows : — 



Excelsior and creosote. 

 Excelsior and Carbolineum. 

 8awdust and creosote. 

 SaAvdnst and Carbolinenm. 

 Asbestos and creosote. 

 Asbestos and Carbolinenm. 

 Asbestos and arsenate of soda. 

 Oakum and creosote. 

 Oakum untreated. 

 Cocoa fiber and creosote. 



