341 



tho autumn, tlio winter, on<l early in the spring, wlien the activity ol 

 vegetation was suspended, which does not seem to have been the case 

 respecting those of Hassenfratz. 



It appears, however, that both lliichert and Scnebier ascertained, 

 tliat vegetables do decompose carbonic acid, retaining tho carbon, and 

 emitting the oxygen. Dr. Woodward made many experiments with 

 I)lants of mint growing in water, and found that a plant, in water from 

 the Thames, which must certainly have contained a large share of 

 carbonic acid, increased considerably more in weight, than a plant 

 growing in pure water. Schoppett, who examined the temperature of 

 growing trees in New- York, found, that from November to April, when 

 the bulb of a thermometer was put into a hole made in a tree, the mer- 

 cury rose higher than in the open air ; and that the colder the weather, 

 the greater of course, was this difference. From April to November, 

 on the other hand, the thermometer showed a lower temperature in the 

 tree, than in the open air. And Ingenhoutz found, that a piece of green 

 paper, hung on a tree, in a warm summer-day, felt sensibly warmer 

 than the leaves. Hunter likewise, who was fond of trees, used to 

 keep thennometers in them for months together, and obtained similar 

 results. — The subject is curious, and is the more deserving of the 

 planter's investigation, that the state of the bark, and its power, when 

 thick and indurated, to protect the sap-vessels, are so intimately con- 

 nected with all facts, that tend to illustrate the subject. 



Note V. Page 101. 



Of the close analogy, which subsists between the animal and vegetable 

 kingdoms, many other examples respecting the former might be adduced, 

 besides those mentioned in the text, in order to show, how universally 

 nature generates provisions for individuals, in order to fit them for the 

 situations, in which they are placed. The general rule seems to be, as 

 mentioned in the text, that where there is a great external application of 

 cold, an adequate non-conducting covering is supplied, to prevent the sub- 

 traction of internal caloric ; and in the same way, that covering is 

 withdrawn, on a greater application of heat. Of the latter the coach 

 or race-horse furnishes a familiar example, with his smooth and silky 

 coat, enjoying the warmth and shelter of a well-constructed stable, 

 when we compare it with the rough and shaggy one which he wears, 

 when running out in winter. The coats of warm-blooded animals 

 appear to be thick and fine, in proportion to the intensity of the cold 

 they are destined to endure ; and they are always thicker and finer in 



