Observations on the structure and economy of plants: to which is added the analogy between the animal and vegetable kingdom / [Robert Hooper].

  • Hooper, Robert, 1773-1835
Date:
1797
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the structure and economy of plants: to which is added the analogy between the animal and vegetable kingdom / [Robert Hooper]. Source: Wellcome Collection.

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    draw from them, as it were, by chemical affi¬ nity, pure vital air. Heat does not appear to contribute any thing, for the evolution of vi¬ tal air is more powerful in the cold, than in heat. All the parts of plants, from which no vital air can efcape, and which abound with it, ex¬ hibit a white and variegated colour : as Fungi, the corollae of plants, immature apples, barks, the bracftese of the Melampyrus nemorofus, the Verrucarlae, Lichen miniatus and parletlnus, and all green plants in an obfcure fituation, as Af- paragus covered with earth, <kc. A dead or difeafed plant exhales nothing, or only impure air; and it is wonderful that fome healthy plants do the fame, although expofed to the folar rays ; as the Ilex aqulfo- Hum, Prunus lauro-cerafus, Mimofa fenfitlva, and Acer folils variegatls. By infpiration plants inhale their nutritious vapours ; and by expiration, they appear to free themfelves from thofe which are fuper- fluous, left they be too much irritated by them. Thefe two operations conftitute the primary life of the refpiration of vegetables.