168 APPLICATION OF PRINCIPLES. 



acid to make old seeds germinate. The seeds are put 

 into a bottle filled with oxalic acid, and remain there 

 till the germination is observable, which generally 

 takes place in from twenty-four to forty-eight hours ; 

 when the seeds are taken out, and sown in the usual 

 manner. Another way is to wet a woollen cloth 

 with oxalic acid, on which the seeds are put, and it is 

 then folded up and. kept in a stove ; by this method 

 small and hard seeds will germinate equally as well 

 as in the bottle. Also very small seeds are sown in 

 pots and placed in a hot-bed ; and oxalic acid, much 

 diluted, is applied twice or thrice a day till they begin 

 to grow. Particular care must be taken to remove 

 the seeds out of the acid as soon as the least vegeta- 

 tion is observable. Mr. Otto found that by this means 

 seeds which were from twenty to forty years old 

 grew, while the same sort, sown in the usual manner, 

 did not grow at all (Gard. Mag., viii. 196) : and it is 

 asserted by Dr. Hamilton (lb., x. 368, 453,) and 

 others, that they have found decided advantages from 

 the employment of this substance. Theoretically 

 it would seem that the effects described ought to be 

 produced, but general experience does not confirm 

 them ; and it may be conceived that the rapid abstrac- 

 tion of carbon, by the presence 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 length of time that some seeds will lie in the 

 ground, under circumstances favourable to germi- 



