On the atmospheric germ theory and origin of infusoria : a lecture delivered to the Royal College of Surgeons of Edinburgh, 17th January 1868.

  • Bennett, John Hughes, 1812-1875.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: On the atmospheric germ theory and origin of infusoria : a lecture delivered to the Royal College of Surgeons of Edinburgh, 17th January 1868. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    The idea that there are such things as histological organic forms, which are necessarily indicative of life, must now be regarded as fallacious. It has deceived many, and among the rest, as we have seen, M. Pasteur. What now interests us are the transformations which these forms undergo, and the passage of one into the other. This inquiry must lead us to the molecular theory of organization, which inculcates that all the tissues are formed by the successive production of histogenetic or formative, and histolytic or disinte- grative molecules ;^ and it appears to me that its correctness is sin- gularly confirmed by the investigations that have been brouglit before you this evening. In short, we have first molecular deposi- tions in organic fluids ; these aggregate to form nuclei, cells, and other tissues; and these again, by constantly breaking down and re-forming, gradually elaborate and build up the higher organisms. It would appear that nature is constantly operating in the or- ganic and inorganic worlds by the process of molecular coalescence ; that the notion of every particle being necessarily derived from its like is erroneous; and that the law of descent from parents, which we recognise in the higher animals, changes, as we descend in the scale, first to parthenogenesis^ whereby this direct descent is broken, and ultimately to heterogenesis, in which it is lost. This theory irresistibly recalls to our recollection the philosophical speculations of the Greeks, and especially of Deraocritus, Anaxagoras, and Empedocles, and suggests to us that history in science, like history in morals or in politics, often repeats itself, so that our pre- decessors may often be regarded not only as the originators of spec- ulative opinions in the past, but also as prophets, who have foretold in the cycle of events the deductive truths of the future. III.—The doctrine that life must necessarily spring from life is essentially connected with the view of direct descent from parents. Previous to the time of Harvey, life was considered to be an inde- pendent principle, capable of being added to or removed from inert matter. Such was the opinion of the ancient philosophers, as alle- gorically explained by the fable of Prometheus, who animated the marble statue by fire stolen from heaven. In later times, BufFon imagined life, like matter, to be indestructible. According to him every living molecule had a life of its own, and the method by which it manifested its function depended on its association with other molecules. Thus, the body of an animal or a plant was the aggregation of a multitude of minute living beings arranged in a particular way. The death of the complex compound was simply a dissolution of one of these associations, and the organic molecules thus set at liberty wandered about until they once more combined with a plant or animal—herewith a monad, there with a quadruped. The materia vitce diffusa of John Hunter was something similar. Our modern view of life is, not that it is independent of matter, ^ See the author's paper on the Molecular Theory of Organization. Proceed- ings of the Royal Society of Edinburgh, April 1,1861; and Microscopical Jour- nal, 1861.