GElirEKAL PfilNCIPLES AND METHODS. 143 



ing the germination of old Spruce seeds and of other coni- 

 fers. Humbolt is said to have employed a dilute solution 

 of chlorine with great success in sprouting seeds ; and 

 another German, a Mr. Otto of Berlin, employed oxalic 

 acid to make old seed germinate. Dr. Lindley, in his 

 "Theory of Horticulture," describes Mr. Otto's method 

 of using oxalic acid, and says that " the seed were put in 

 bottles filled with the acid and left in it until they germi- 

 nated, which generally takes place in from twenty to 

 forty-eight hours." The seeds are then removed and 

 sown in the usual way. Very small seeds may be sown 

 and diluted acid applied two or three times a day until 

 they germinate. 



Mr. Otto claimed that by this means, seeds that were 

 from twenty to forty years old grew, while the same sort, 

 sown in the usual manner, did not grow it all. But Dr. 

 Lindley, in referring to the advantages claimed for the 

 acid process, says : " Theoretically it would seem that 

 the effects described ought to be produced, but general 

 experience does not confirm them ; and it may be con- 

 ceived that the rapid abstraction of carbon by the pres- 

 ence of an unnaturally large quantity of oxygen may 

 produce effects as injurious to the health of the seed as 

 its too slow destruction in consequence of the languor of 

 the vital principle." 



The oxalic acid solution for accelerating the germina- 

 tion of seeds, although highly extolled at the time of its 

 discovery, has, like many other similar discoveries, gone 

 out of use and is almost forgotten. At the present day 

 our horticulturists depend mainly upon heat and moisture 

 for revivifying the dormant energies of their old as well 

 as new seeds, although, as I have said, the alkaline soln- 

 tions are very useful in softening and removing natural 

 incrustations of some kinds, and the hard, horn-like 

 covering of others. Frost, or freezing, is also useful for 

 this purpose, and always available in cold ciiinates ; but 



