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Dr. J. B. Sanderson on the Attributes of [Nov. 22, 



living material. Even the simplest instance that we can mention, that of 

 the elevation of dead albumen into living (a process which in the case 

 now before us must represent the very earliest step in the climax of 

 development), is at the present moment beyond the reach of investigation ; 

 for as yet we are only beginning to know something about the constitu- 

 tion of non-hving proteids. But this want of knowledge of the nature 

 of the difference between living and non-living material in no wise im- 

 pairs the conviction which exists in our minds that the difference is one 

 of molecular structure. 



The sum of the preceding paragraphs may be stated in few words. 

 Wherever those chemical processes go on which we collectively desig- 

 nate as life, we are in the habit of assuming the existence of ana- 

 tomical structure. The two things, however, although concomitant, 

 are not the same ; for while anatomical structure cannot come into 

 existence without the simultaneous or antecedent existence of the kind 

 of molecular structure which is peculiar to living material, the proof is 

 at present wanting that the vital molecular structure may not precede 

 the anatomical. At the same time it must be carefully borne in mind 

 that there is no evidence of the contrary. It is sufficient for my pur- 

 pose to have shown that the existence of organized particles endowed 

 with anatomical structure in the " atmospheric dust " has not been proved. 

 I do not dispute its probability. 



Before leaving this subject I may be permitted to add a word as to the 

 bearing of this discussion on a question which, to myself, is of special 

 interest — that of contagium vivum. According to the view which these 

 words are understood to express, the morbific material by which a con- 

 tagious disease is communicated from a diseased to a healthy person 

 consists of minute organisms called "Disease-Germs." In order that 

 any particle may be rightly termed a Disease-Grerm two things must be 

 proved concerning it, viz. : — first, that it is a living organism ; secondly, 

 that if it finds its way into the body of a healthy human being, or of an 

 animal, it will produce the disease of which it is the germ. Now there is 

 only one disease affecting the higher animals in respect of which any 

 thing of this kind has been proved, and that is splenic fever of cattle. 

 In other words, there is but one case in which the existence of a disease- 

 germ has been established. 



Compariug such a germ with the germinal particles we have been dis- 

 cussing, we see that there is but little analogy between them : for, first, the 

 latter are not known to be organized ; secondly, they have no power of 

 producing disease ; for it has been found by experiment that ordinary 

 Bacteria may be introduced into the circulating blood of healthy animals in 

 considerable quantities without producing any disturbance of health. So 

 long as we ourselves are healthy, we have no reason to apprehend any 

 danger from the morbific action of atmospheric dust, except in so far as 



