A new system of vegetable physiology : designed to account satisfactorily for the phenomena which take place in the vegetable kingdom, and to shew the influence of heat, light, and electricity on vegetation / by Daniel Vaughan.

  • Vaughan, Daniel, 1821-1879.
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: A new system of vegetable physiology : designed to account satisfactorily for the phenomena which take place in the vegetable kingdom, and to shew the influence of heat, light, and electricity on vegetation / by Daniel Vaughan. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    5/26
    VEGETABLE PHYSIOLOGY. 1. To acquire a knowledge of the nature of vegetation, and to> understand the various circumstances on which it depends, it is necessary to examine several facts, which science or practical obser- vation has made known respecting vegetables. Chemistry, in its pre- sent improved state, has enabled us to discover their compostion, their structure, and the many changes to which they are subject; while equally important discoveries, with regard to their growth, have result- ed from continual experience in the art of culture. Of the informa- tion collected from these sources I have freely availed myself, in the formation of theory contained in the following pages. The principles on which it is founded I shall endeavor to explain in a very concise manner, as I intend to treat more fully on the subject on some future occasion. The necessity of a well established theory on vegetation, is manifest to all conversant with the contradictory opinions, which, have been advanced on the subject by writers on Vegetable Phy- siology. 2. Every inquisitive observer of nature, on taking a survey of the vegetable kingdom, must be led to inquire: From what source do plants derive their food? In what manner is this food conveyed to them? What renews the supply and prevents it from being exhaust- ed] I shall proceed to examine and to answer these important ques- tions which have, for a considerable time, occasioned so much con- troversy between chemists and vegetable physiologists. Indeed, most of the vague and erroneous opinions on this subject, may be traced to the loose method of reasoning adopted by many theoretical writers, whose systems are based upon a supposed analogy between all the operations of nature. By them, the flow of the sap in trees, is com- pared to the circulation of the blood in animals ; the decomposition of carbonic acid, by the leaves of plants, is ascribed to the same princi- ple which causes its formation in our lungs, during respiration: ve- getables are supposed to possess juices and organs corresponding to those of animals, and performing similar functions; while all the cir- cumstances attending their growth, are imagined to be sufficiently ex- plained when compared to some operation of animated nature. There is, indeed, no proof that such analogies should necessarily exist; and,, even if there were, comparisons of this kind would throw little light on vegetation, as the animal functions are, perhaps, more difficult to be