Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ; with notes by Richard Owen.

  • Hunter, John, 1728-1793.
Date:
1841
Catalogue details

Licence: Public Domain Mark

Credit: Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ; with notes by Richard Owen. 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.)

    18/488
    The present seems, therefore, to be a ***J**^ \°0 attempt to define the grounds for assigning a higher stanon^ Hunter, considered as a physiologist and comparative anatomist In this endeavour, however, to prove what Hunter was as a coverer, we must also fairly state what he was not He has been spoken of as the originator of the idea of a subtte imponderable principle operating in the fluids and -o^s of the organism, and causing the phenomena of life. But s^ ■P™ ciple, under various names and with various attributes, has been assigned as the cause of organization by Aristotle, Harvey, Willis, Cudworth, Grew, Van Helmont, and Stahl. . . \s both Harvey and Hunter had spent laborious lives in earnest inquiries and repeated dissections and experiments to ascertain relations between structure and function; as both had studied the changes which take place in the form and structure of animals from their embryo state to that of maturity ; and as both had care- fully traced the successive phenomena which occur in the egg during incubation,—the similarity of their opinions on the nature and powers of the vital principle is correspondingly close. Both arrived at the conclusion, that an animating principle exists and operates in the ovum prior to the formation of any organ of the future animal. Both attributed the power by which the iecund egg resists putrefaction, while the unprolific one decomposes, to a principle of life, which Harvey more precisely terms the anima vegetiva.* Hunter, however, carries his researches a step further; he sub- mits the fecund egg to a low temperature, and ascertains a new property, of which Harvey was ignorant, a power, viz., of resist- ing cold: he also shows that when once frozen, and killed by cold, the dead impregnated egg yields to putrefaction like the unimpreg- nated one. Both physiologists observed that if the phaenomena of a vital principle were manifested in one part of the organization more than in another, it was in the blood. For the blood,'-' says Harvey, is the first formed, and is the primary animate particle of the em- bryo; it is generated prior to the punctum saliens, before the first rudiment of the heart, and is endowed with the vital heat or princi- ple before it begins to move, and from it does pulsation commence. *Plurimum itaque mecum ipse repntavi, qui fieret, ut ova improlifieagat linae supposita, ab eodem calore extraneo corrumpantur, putrescant, et foetid a evadant; ovis autem fcecundis idem non contingat. Harveii Be Generatione .'inimalium Exercitatio 22. Ovum itaque est corpus naturale virtute animali praeditum ; principio nempe motus, transmutationis, quietis, et conservationis. Exercit. 26. Cum enim in ovo macula prills dilatelur, colliquamentum concoquatur et praeparetur, plurimaque alia (non sine providentia) ad pulli formationem et in- cremental!] instiluantur, anteqnam quidpiam pulli vel ipsa primogenita ejus particula appareat; quidni utique credamus calorem innatum animamque pulli vegetativam ante pulium ipsum exsistere ? Exercit. 57.