TO HASTEN GERMINATION. 275 



water to increase the germinative vigor of seeds, about 

 which much has been written of late, will not now be dis- 

 cussed, but simply dismissed with the statement that the 

 latest researches do not support the claims previously ad- 

 vanced for this agent. The results have generally been 

 negative and unsatisfactory. 



No presentation of the subject of the action of chemical 

 agents upon germinative power, or upon seeds in general, 

 can be complete without copious references to the investi- 

 gations by Gary Lea of Philadelphia ; but at this time I can 

 only hope to give the results of later studies, and chiefly 

 with reference to the destruction of fungi upon seeds. In 

 the work of Nobbe, to which so many references have been 

 made during this lecture, will be found a list of more than a 

 hundred chemical substances which have been employed to 

 prepare seeds for planting. Of these only chlorine-water, — 

 which, in a very dilute state, appears to hasten the process of 

 germination, and not very unmistakably, either, — and dilute 

 solutions of blue vitriol, or sulphate of copper (to destroy 

 smut and the like), have a creditable record. To the general 

 statement that dilute solutions of sulphate of copper do not 

 much impair the vitality of seeds, while in some cases they 

 appear to be efficacious in destroying the fungus, may be 

 added two recent observations not given in Nobbe : — 



1 . Kudelka * placed two packages of three hundred grains 

 of wheat under different treatment, as follows : the grains 

 in one package were soaked for sixteen hours in half-per-cent 

 solution of blue vitriol, the grains of the other in distilled 

 water, and they were then made to germinate in sets of one 

 hundred in the testing apparatus of Nobbe (to be by and by 

 described), — one hundred in earth half a centimeter, or one- 

 fifth inch, deep ; and one hundred in earth a little over an 

 inch deep. 



1 Biedermann's Centralblatt, 1876, 10-192. 



