OF SEED-SOWING. 163 



At 118°, under the same ciroumstanoes most of them perished. 

 122°, ditto ditto, all perished. 



But it was found that, for short periods of time, a 

 much higher temperature could be borne. 



At 143-6°, in vapour, Wheat, Barley, Kidneybeana, and Flax retain- 

 ed their vitality for a quarter of an hour ; but in 27^ mi- 

 nutes, the three last died. at a temperature of 125'6°. 



16T°, in vapour, they all perished. 



1&'1°, in dry air, they sustained no injury. 



It will be presently seen that some seeds will bear 

 a much higher temperature. 



The foregoing observations apply to seeds in a per- 

 fect state of health ; when they have become sickly 

 or feeble, from age or other causes, some precautions 

 become necessary, to which, under other circum- 

 stances, no attention requires to be paid. 



When the vital energies of a seed are diminished, 

 it does not lose its power of absorbing water, but it is 

 less capable of decomposing it (14). The conse- 

 quence of this is, that the free water introduced into 

 the system collects in the cavities of the seed, and pro- 

 duces putrefaction ; the sign of which is the rotting 

 of the seeds in the ground. The remedy for this is to 

 present water to the seed in such small quantities at a 

 time, and so gradually, that no more is absorbed than 

 the languid powers of the seed can assimilate ; and to 

 increase the quantity only as the dormant powers of 

 vegetation are aroused. One of the best means of 

 doing this is, to sow seeds in warm soil tolerably dry ; 

 to trust for some time to the moisture that exists in 

 such earth, and in the atmosphere, for the supply re- 



