14 



cept that we have in this an indication of injury to seed, not by the 

 crude oil of lemon or by the terpenes but by the terpeneless oil. Why 

 this injury should appear in these experiments and not in the preced- 

 ing, I am unable to explain except on the supposition that the two sets 

 of pots received different amounts of water, the reasons for which 

 supposition will appear later. The proportions of oil of lemon and 

 terpeneless oil in the mixtures are the same in this table as in the pre- 

 ceding one. In the last of these experiments the alcohol mixture with 

 oil of lemon contained terpenes to the amount of 5, 10, and 20 per 

 cent respectively in the different lots ; but as these do not vary in their 

 average effect upon the seed, they are here thrown together. 



Pot Plantings of Corn Tre.\ted with Ordinary Lemon Oil, Terpeneless 

 Lemon Oil, and Pure Terpenes, September 5, 1907 



Treatment 



Per cent of plants up 



None (check) 



Lemon oil with alcohol 



Terpeneless lemon oil with alcohol. 

 Lemon oil and terpenes with alcohol 



September 



!=£:i 



0= a 

 T, to 





3.27 

 3.53 

 2.9 

 3.15 



Still another experiment, begun September 8, differed from the 

 others in the much stronger solutions of the essential oils. These were 

 used at the rate of .75 of an ounce of the oils to the gallon of corn, 

 making solutions about two and a half to three times as strong as those 

 previously used. In this series we have clear confirmatory evidence of 

 the injurious effect of the terpeneless oil. and also of a lesser injury by 

 the ordinary lemon oil, as is shown by the following table. 



Pot Plantings Treated with Ordinary Lemon Oil, Terpeneless Oil, 

 AND Terpenes, September 8, 1907 



Treatment 



Per cent of plants up 



^1 



16 



September 

 17 I 19 I 



22 



CO\ 



.a Q. 

 bo <u 

 •r, LO 



<;.s 



None (check) 



Lemon oil 



Terpeneless lemon oil 

 Terpenes 



100 

 200 

 200 

 200 



74 



38 



5 



59 



78 

 56 

 16 

 68 



80 I 80 



66 I 68 



23 27 



69 71 



4.87 

 3.69 

 2.19 

 4.75 



