42 



On the Hombothermal method of Acclimating 



[Jan. 



identity of the vital principle which governs both animal and vegetable 

 existence. 



Mr. Anderson commenced his experiment, by changing, through the 

 application of the stimulus of heat to the gejnrinating seed, the character 

 of his subjects, from hardy extra- tropical, to tender tropical plants, and 

 then concludes, that they are naturally too tender to withstand the cold 

 nights of an English autumn. Mr. Speed by the application of heat, at 

 precisely the same stage of their existence, changes his from hardy to 

 tropical plants, and then successfully rears them in a tropical climate. 

 Both are surprised at the] result, while in truth, on the principles here 

 explained, the success of the one was as certain as the failure of the 

 other. Had Mr. Anderson sown his seed in autumn, in the open air, 

 as he would have done winter wheat, and as is done in their native 

 country, their power of resisting the cold of its almost Siberian climate, 

 would easily have protected them against the much milder winter of 

 England ; while their excitability, accumulated by the long privation 

 of the stimulus of heat, would have prepared them to start vigo- 

 rously on their course to maturity with the first heats of spring, 

 and, in all probability, they would have matured their crop in the 

 course of the summer or early in autumn. Mr. Speed having foil- 

 ed in rearing celery by adopting the contrary practice, with most 

 commendable perseverance, determined to sprout his seeds in a hot 

 bed, and is rewarded by the possession of a plot of fine celery in 

 May. From this it would appear, that plants raised from European 

 seeds, if germinated in cool shaded beds, regain in a high degree 

 their excitability, unfitting them for successful culture nn a hot cli- 

 mate; but which is exhausted by the application of heat to the ger- 

 minating seed, and their constitutions so modified and assimilated 

 to the climate, as not only to resist a high temperature, but even 

 to render it necessary to their after existence. 



Does the seed of plants so altered, retain the tropical character com- 

 municated to the parent ? 



In the present state of our knowledge it is impossible to answer 

 this question, as not a single fact exists directly bearing on the subject : 

 but, reasoning a priori, I can see no reason for doubting that they 

 would in the second, if not in the first generation ; and if numerous 

 and carefully conducted experiments prove this to be the case, I have 

 no hesitation in assuming, that the two experiments which form the 

 basis of this communication, have led to the most important and valu- 

 able discovery ever made in the science of agriculture, in connection 

 with vegetable physiology. It is almost superfluous to add, that the 

 obvious deduction from them is, that we may, if we choose, see the 

 plains of India, and not of India only, but of the whole torrid zone, 

 covered with the highly nutritious grains and roots of Europe, in place 

 of the very inferior ones now in use. Nor need we confine ourselves 



