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TEE POPULAR SCIENCE MONTELY.— SUPPLEMENT. 



fore, is the determination of the elementary prop- 

 erties of living tissues. 



It is the part of descriptive physiology to 

 show how these tissues are combined in different 

 organs, according to the various species of ani- 

 mals, and to explain functions by the action of 

 those elementary properties of living matter of 

 which they are only the resultants. Wherever 

 any tissue takes its place, it takes it with such 

 and such properties ; the muscular tissue will be 

 everywhere endowed with the property of con- 

 tracting, the nervous tissue everywhere endowed 

 with the property of transmitting sensations or 

 motion. The tissues, in turn, are not the last 

 elements of the organization ; beyond the tissues 

 we detect the true organic element, which is the 

 cell. Thus the functions of the organs will be 

 nothing more than the various actions of the 

 cells that compose them. Hence we see that 

 form and structure, important though they may 

 be from the point of view of descriptive physiol- 

 ogy, play only a secondary part in general phys- 

 iology. 



Another physiologist, M. Charles Robin, whose 

 authority in histology and micrography is ac- 

 knowledged, expresses ideas similar to those of 

 M. Bernard on this subject, and even goes further 

 than he does. M. Bernard, while restricting sci- 

 ence to the examination of the elementary prop- 

 erties of living matter, by no means excludes the 

 idea of intelligent mechanism in the construction 

 of the organism. It is, on the contrary, for M. 

 Robin, an obsolete and wholly false idea to con- 

 ceive of the organization as a machine. That 

 opinion, made known and brought into vogue by 

 the school of Descartes, was expressed in these 

 terms by the famous English physician, Hunter : 

 "The organism," he said, "may be reduced to 

 the notion of the mechanical association of the 

 parts." This cannot be maintained in the pres- 

 ent state of science. Such a course of thought 

 would lead us to believe that organization may 

 exist without the existence of life : thus, if Hun- 

 ter be right, a corpse, as long as its elements are 

 not dissociated, would be as well organized as a 

 living body. A grave error ! Organization can- 

 not exist without its essential properties, and 

 what is called life is the union of these proper- 

 ties in action. The instance of fossils completely 

 proves that mechanical structure is only one of 

 the consequences of organization, not organiza- 

 tion itself. In fossils, in fact, form and structure 

 are maintained indefinitely, though the imme- 

 diate principles that composed them have been 

 destroyed and replaced, molecule by molecule, 



through fossilization ; not a trace remains of the 

 animal or plant, though its structure is mathe- 

 matically preserved, even to the minutest details. 

 We seem to touch a being that once lived, that 

 is still organized, and yet we have only brute 

 matter under our eyes. Not only may structure 

 or mechanical combination exist without there 

 being any organization, but, reciprocally, organi- 

 zation may exist before any mechanical arrange- 

 ment. To make this quite intelligible, the learned 

 physiologist reduces the increasing complication 

 of the parts of the organism to a graduated 

 scale, placing at the lowest degree the anatomi- 

 cal elements, or cells, above them the tissues, 

 next the organs, then the apparatuses, lastly the 

 complete organisms. An organism — an animal 

 ©f the higher order, for instance — is composed of 

 different apparatuses, of which the acts are called 

 functions; these, again, are made up of different 

 organs, which, by virtue of their conformation, 

 have such or such a use ; these organs in turn 

 are composed of tissues, the arrangement of 

 which is called texture or structure, and which 

 have properties; these tissues themselves, in fine, 

 are made out of elements or cells, which some- 

 times appear with a certain structure and a defi- 

 nite figure (the cell and the nucleus), and take 

 the name of organic elements having form, and 

 sometimes appear without any structure at all, 

 as an amorphous, homogeneous substance : such 

 are the marrow of the bones, the gray matter 

 of the brain, etc. 



M. Robin's statement is this, that the essen- 

 tial characteristic of organization is not mechan- 

 ical structure, but is a certain mode of molecular 

 association among the immediate principles; * 

 whenever this mode of association exists, the 

 organized substance, whether with or without 

 structure — whether amorphous or shaped — is en- 

 dowed with the essential properties of life. These 

 properties are five in number: nutrition, growth, 

 reproduction, contraction, and innervation. The 

 five vital properties essential to the living being 

 are not found in all living beings ; but they may 

 be united in all, independently of any mechanical 

 structure. Therefore, the study of the organs 

 and of their functions is nothing but the study 

 of the different combinations of the organic ele- 

 ments and of their properties. 



If, now, we reflect on the vital properties, and 

 the first of them all, nutrition, we shall see still 

 more plainly the radical difference there is be- 



1 Immediate principles is the name given to those 

 chemical compounds, ternary or quaternary, whicSi 

 are almost or quite peculiar to organized beings. 



