THE RANGE OF NATURE'S OPERATIONS. 221 



tions and events in biolog^^can extend over a duration which is appre- 

 ciable by us, even in the case of explosions, the fact being that in all 

 such events it is their excessive slowness from the molecular stand- 

 point that has to be accounted for. On the other hand, the frequency, 

 when estimated from the human standpoint, of events which are excess- 

 ively rare when viewed from the molecular standpoint, has enabled 

 all the constituents of an atmosphere to escape from the moon in the 

 time which has elapsed since the moon became separated from the 

 earth, and occasions such a leaking away from the upper regions of 

 the earth's atmosphere of hydrogen and helium, the atmosphere's 

 lightest constituents, as would become appreciable within a few mil- 

 lions of years were it not that these gases are being continuously 

 filtered into the atmosphere from beneath. 



CONCLUSION. 



No physicist can consult the diagram presented in figure 1 without 

 being struck by its resemblance to an absorption band in a spectrum. 

 Nature is occupied in working everywhere over the entire spectrum; 

 man's knowledge of her works is confined to what occurs within this 

 one absorption band. How much changed would be the aspect under 

 which the human mind would have had to view nature if the position 

 of the absorption band had occupied a difi'erent place — if, for example, 

 the range of our knowledge had been Groups B, C, D, and E, instead 

 of A, B, C, and D, with such a full knowledge of molecular objects 

 and events as we now enjoy of objects that range from kllems down to 

 microns, and with such a lessened knowledge of Group C as we now 

 have of planetar}' events! An equallv startling change would be made 

 if the range had been shifted the other way — if we had no knowledge 

 of microscopic or molecular events, just as we now possess none of 

 those which go on within and beyond subsection -w of Group D; if, at 

 the same time, we had only a smattering of knowledge about Group 

 C, such as the fragments we are now able with difiicultv to obtain 

 about Group D, accompanied, however, by some real ac(|uaintance 

 with the inmiense universe that lies beyond Group A. 



Along with these considerations we should ever bear m mind that 

 behind and above the great universe, of natural objects, and the true 

 cause of all the rest, there stands the Autic Universe, the mighty 

 Autos, to which the present writer endeavored to draw attention in an 

 earlier paper, and of which the thoughts that are our real selves are 

 part. (See Scientific Proceedings of the Royal Dublin Society, Vol. 

 VI (1890). page 47.5.) 



APPENDIX. 



A standard model of molecular phenomena is described above, in the 

 footnote on page 219. 



The writer can strongly recounuend the corresponding standard 

 model of celestial phenomena. This is made by taking tenthets of all 



