July 24, 1916 Properties of the Virus of Mosaic Disease 



659 



TREATMENT OF DRIED MOSAIC MATERIAL WITH ETHER, 

 •CHLOROFORM, AND OTHER SOLVENTS 



In the following experiments dried and ground mosaic material, desig- 

 nated as X 13 , was used. The original green leaves were harvested on 

 August 31, 191 5, and dried in the air. For each solvent the procedure 

 was as follows : Ten gm. of air-dry material were extracted with 70 c. c. of 

 extractive for two days. This solution was then filtered through paper 

 and 35 c. c. of the filtered solution were set aside in a small beaker to 

 evaporate at room temperatures. The residue left after evaporation 

 was brought into 5 c. c. of distilled water and used for inoculation. The 

 original residue, X 13 , left after filtering off the solvent, was then thor- 

 oughly dried at room temperatures and macerated with 50 c. c. of dis- 

 tilled water in a mortar. Ten c. c. of the extract were used for inocula- 

 tion. In this way the infective properties of the extract and of the 

 original material from which this extract was obtained could be compared. 



The process w r as somewhat different w 7 ith glycerin, as this is not read- 

 ily evaporated. After extracting 10 gm. of the dry material for two 

 days the glycerin extract was pressed out and filtered through hard 

 paper under reduced atmospheric pressure. Of the filtered solution 40 

 c. c. were then made up to 800 c. c. with distilled water, giving a 5 per 

 cent glycerin solution, which will produce no injury when inoculated 

 into tobacco plants. After filtering off the glycerin extract the original 

 X 13 residue was then subjected to pressure to remove as much glycerin 

 as possible and was then macerated in a mortar with 50 c. c. of distilled 

 water. The results obtained for each solvent are shown in Table VII. 



Table VII. — Effect of digestion with ether, chloroform, and other solvents upon infec- 

 tivity of mosaic material X 13 dried at room temperatures in IQ15, 10 plants having been 

 used in each test 



Solvent used. 



Residue X 13 after digestion with 



ether. 



Ether extract of X 13 



Residue X 13 after digestion with 



chloroform. 



Chloroform extract of X 13 



Residue X' 3 after digestion with 



carbon tetrachlorid. 

 Carbon tetrachlorid extract of X 13 . 

 Residue X 13 after digestion with 



toluene. 



Toluene extract of X 13 .' 



Residue X 13 after digestion with 



acetone. 



Acetone extract of X 13 



Residue X 13 after digestion with 



ethyl alcohol. 



Ethyl alcohol extract of X 13 



Residue X 13 after digestion with 



methyl alcohol. 



Methyl alcohol extract of X 13 



Residue X 13 after digestion with 



glycerin. 



Glycerin extract of X 13 



Residue X 13 after digestion with 



water. 

 Water extract of X 13 



Tap water (control) . 



Period of 

 extraction. 



Oct. 6 to 8.. 



.do. 

 .do. 



.do. 

 .do. 



.do. 

 .do. 



do. 

 .do. 



...do 



Oct. 8 to 10. 



do. 

 do. 



.do. 

 .do. 



do 

 do. 



.do. 



Time required 



for extract to 



evaporate. 



Oct. 8 to 16.. 



Oct. 8 to 12.. 

 Oct. 8 to 16. . 



Oct. 8 to 12.. 

 Oct. 8 to 16.. 



Oct. 8 to 12.. 

 Oct. 8 to 16.. 



Oct. 8 to 12.. 

 Oct. 8 to 16.. 



Oct. 8 to 12.. 

 Oct. 10 to 16. 



Oct. 10 to 13. 

 Oct. 10 to 16. 



Oct. 10 to 15. 

 Not evapo- 

 rated. 



...do 



Oct. 10 to 16. 



Not evapo- 

 rated. 



Date 



taken up 



with 



water. 



Oct. 16 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 

 Oct. 



Oct. 



Peroxidase 



reaction 

 after treat- 

 ment. 



Very weak . 



None 



Very weak . 



None 



Very weak . 



None 



Very weak . 



None 



Very weak . 



None., 

 Weak. 



None 



Very weak . 



None 



Very weak . 



.do. 

 .do. 



Good. 



Results of 



inoculating 



plants Oct. 19, 



1915- 



8 mosaic. 



All healthy. 

 10 mosaic. 



All healthy. 



5 mosaic. 



AH healthy. 

 10 mosaic. 



All healthy. 

 8 mosaic. 



All healthy. 

 Do. 



Do. 

 Do. 



Do. 



6 mosaic. 



10 mosaic. 

 Do. 



8 mosaic. 



All healthy. 



42720° 



