66o 



Journal of Agricultural Research 



Vol. VI, No. 17 



In the test with glycerin the material to which the glycerin had been 

 added was subjected to maceration and pressure in order to obtain the 

 extract. A later experiment would seem to indicate that if the glycerin 

 extract is poured off without subjecting the residue to maceration or 

 pressure the extract will contain little, if any, of the infectious principle. 

 In this experiment 10 gm. of the same X 13 material were used. This 

 material, however, was dried over sulphuric acid in a desiccator from 

 November 8 to November 23, 191 5. On November 23, 80 c. c. of glyc- 

 erin were added and allowed to stand until November 27, when the dark- 

 colored extract was merely poured off and filtered through hard paper 

 under reduced atmospheric pressure. Solutions containing 8 and 20 per 

 cent of the extract were made, distilled water being used to dilute the 

 glycerin. 



The dry material from which the glycerin extract had been poured off 

 was now washed with 100 c. c. of distilled water. This was poured off 

 and filtered through hard paper, and the material was again washed with 

 380 c. c. of distilled water. This solution was also poured off and filtered 

 through hard paper. The original leaf material, which was now fairly 

 free from glycerin, was macerated with 25 c. c. of distilled water. The 

 results of testing the above solutions and material for peroxidase and 

 infection are given in Table VIII. 



TABLE VIII. — Results of inoculations with dried material X 13 digested with glycerin in 

 IQ15, 10 plants having been used in each test 



In order to compare the results with dried mosaic material, green 

 mosaic leaf material was also treated with ether, chloroform, and water. 

 For each solvent 25 gm. of finely cut and macerated green mosaic material 

 were used. The quantity of solvent used was about 100 gm. — that is, 

 140 c. c. of ether, 80 c. c. of chloroform, and 100 c. c. of distilled water. 

 These solvents were added to the green material and shaken on October 

 20. On October 21 all the solution that could be poured off was then 

 filtered through hard paper and set aside in beakers to evaporate in the 

 air. Of the filtered ether solution 115 c. c. , and of the chloroform solu- 

 tion 55 c. c, were obtained. After evaporation, the residues left from the 

 ether and chloroform solutions were each placed in 5 c. c. of distilled 

 water. The leaf material from which these solutions had been obtained 



