Repository: UIHistories Project: Board of Trustees Minutes - 1869 [PAGE 178]

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1«4 Prof. STEWART—I have no doubt with reference to the tempers ture of trees being higher than the air about them. The tree i a living being as much as an animal. As the temperature of an; mals is higher than that of the surrounding atmosphere, so w may expect to find in plants a temperature higher than that of th atmosphere. There is this consideration, also. What is it that i going on when plants are growing ? Plants grow by a series c chemical combinations, and where these changes are going o; there is heat evolved. T o u cannot have chemical action withou heat being evolved. Chemical action is that which produces hea in animal life, and the same is - true in the life and growth of plant* W e should naturally infer this from the nature of the process tha is going on. I also desire to say this respecting the influence c the moon upon the weather, which matter has been alluded to i the lecture. I place no reliance upon the supposition that th moon has any influence upon the weather. I would suggee whether these contradictory results, arrived at by so many carefu observers, are not attributable to local causes. Every section o the country has its peculiar climate, and may not these local cause produce these different results, instead of having to go to th' moon to account for the weather ? Had we not better stay upo] the earth, instead of going off to the moon,, and find causes a home, instead of abroad, for these changes of weather? I think if we understood the matter fully, we should find that the mooi had very little to do with the weather. Dr. GREGORY suggested, in view of the fact which seemed to bi established that trees generate heat, whether they have not, ii this, the power to resist frost. The human sjstem, if frozen, dies H e was inclined to the opinion that if a tree was frozen to tin heart it would die also. But all this looked so much like mer< theory, that it was hardly safe to advance such an idea. Mr. ROBINSON questioned the position of Prof. Stewart that hea always accompanies chemical action. H e was under the impres sion that there were cases of chemical combinations where hea was not evolved. Is it not so? Pi of. STEWART—I know of no instances of this kind. If yoi take the oil of vitriol and mix it with ice, there will be a chemica combination, and there will be produced a very low temperature Still there is at the same time heat produced. I have not th< slightest doubt of this. I know of no instance where there h