Denial 

 Depth 



SCIENTIFIC SIDE-LIGHTS 



158 



tho vague and indefinite, are nevertheless 

 sufficient to form the nucleus of a hazy at- 

 mosphere of religious feeling and emotion. 

 Such men may or may not recognize the fact 

 that these feelings and emotions have been 

 inherited from ancestors whose beliefs were 

 purely theological, and that it is in the high- 

 est degree doubtful how long these feelings 

 can be retained as mere survivals. ARGYLL 

 Unity of Nature, ch. 11, p. 269. (Burt.) 



769. DENSITY OF SUN RELATIVE- 

 LY SLIGHT Contraction and Evolution of 

 Heat Must Still Go On. And the sun is by 

 no means so dense as it may become. Spec- 

 trum analysis demonstrates the presence of 

 large masses of iron and of other known 

 constituents of the rocks. The pressure 

 which endeavors to condense the interior is 

 about 800 times as great as that in the cen- 

 ter of the earth;- and yet the density of the 

 sun, owing probably to its enormous tem- 

 perature, is less than a quarter of the mean 

 density of the earth. HELMHOLTZ Popular 

 Lectures, lect. 4, p. 182. (L. G. & Co., 

 1898.) 



7 7 O. DEPARTMENTS OF MEMORY 



Interest and Habit Control Remembrance. 

 The visual, the tactile, the muscular, the 

 auditory memory may all vary independent- 

 ly of each other in the same individual ; and 

 different' individuals may have them de- 

 veloped in different degrees. As a rule, a 

 man's memory is good in the departments 

 in which his interest is strong; but those 

 departments are apt to be those in which his 

 discriminative sensibility is high. A man 

 with a bad ear is not likely to have practi- 

 cally a good musical memory, or a purblind 

 person to remember visual appearances well. 

 [When we consider the differences in the 

 power of imagination in different men] it is 

 obvious that the machinery of memory must 

 be largely determined thereby. JAMES Psy- 

 chology, vol. i, ch. 16, p. 684. (H. H. & Co., 

 1899.') 



771. DEPENDENCE, 'INSTINCTIVE, 

 OF INSECT ON PROTECTIVE MIMICRY 



A Leaftike Locust. To show how perfect 

 is the protection obtained [by protective 

 mimicry] and how important it is to the 

 possessors of it, the following incident, ob- 

 served by Mr. Belt in Nicaragua, is most 

 instructive. Describing the armies of fora- 

 ging ants in the forest which devour every 

 insect they can catch, he says : " I was much 

 surprised with the behavior of a green leaf- 

 like locust. This insect stood immovably 

 among a host of ants, many of which ran 

 over its legs without ever discovering there 

 was food within their reach. So fixed was 

 its instinctive knowledge that its safety de- 

 pended on its immovability, that it allowed 

 me to pick it up and replace it among the 

 ants without making a single effort to es- 

 cape. This species closely resembles a green 

 leaf." WALLACE Darurinism, ch. 8, p. 138. 

 (Hum.) 



772. DEPENDENCE OF ORGANISM 

 ON ENVIRONMENT Of Soul on God. 

 Powerlessness is the normal state . . . 

 of every organism apart from its environ- 

 ment. The entire dependence of the soul upon 

 God is not an exceptional mystery, nor is 

 man's helplessness an arbitrary and un- 

 precedented phenomenon. It is the law of 

 all Nature. . . . But who will not 

 rather approve the arrangement by which 

 man in his creatural life may have unbroken 

 access to an Infinite Power? What soul will 

 seek to remain self-luminous when it knows 

 that " The Lord God is a sun " ? Who will 

 not willingly exchange his shallow vessel for 

 Christ's well of living water? Even if the 

 organism, launched into being like a ship 

 putting out to sea, possessed a full equip- 

 ment, its little store must soon come to an 

 end. But in contact with a large and boun- 

 teous environment its supply is limitless. 

 In every direction its resources are infinite. 

 DRUMMOND Natural Law in the Spiritual 

 World, essay 7, pp. 241-2. (H. Al.) 



773. DEPENDENCE OF SCIENCE ON 



MECHANICS Scarcely less important for 

 the practical uses of astronomy than the 

 optical qualities of the telescope is the man- 

 ner of its mounting. The most admirable 

 performance of the optician can render but 

 unsatisfactory service if its mechanical ac- 

 cessories are ill-arranged or inconvenient. 

 Thus the astronomer is ultimately depend- 

 ent upon the mechanician; and so excellently 

 have his needs been served that the history 

 of the ingenious contrivances by which dis- 

 coveries have been prepared would supply a 

 subject (here barely glanced at) not far "in- 

 ferior in extent and instruction to the his- 

 tory of those discoveries themselves. 

 CLERKE History of Astronomy, pt. i, ch. 6, 

 p. 149. (Bl., 1893.) 



774. DEPENDENCE OF THE GREAT- 

 EST UPON THE LEAST -Microscopic Or- 

 ganisms Affect the Chief Concerns of Life. 

 This application of biology to life and its 

 problems has in recent years been nowhere 

 more marked than in the realm of bacteriol- 

 ogy. This comparatively new science, asso- 

 ciated with the great names of Pasteur, 

 Koch, and Lister, furnishes indeed a stock 

 illustration of the applicability of pure bi- 

 ology. Turn where we will, we shall find 

 the work of the unseen hosts of bacteria 

 daily claiming more and more attention 

 from practical people. Thus biology, even 

 when clothed in the form of microscopic 

 cells, is coming to occupy a new place in the 

 minds of men. " Its evolution." as Profess- 

 or Patrick Geddes declares, " forms part of 

 the general social evolution." Certainly its 

 recent rapid development forms a remark- 

 able feature in the practical science of our 

 time. Not only in the diagnosis and treat- 

 ment of disease, nor even in the various ap- 

 plications of preventive medicine, but in 

 ever-increasing degree and sphere, micro- 

 organisms are recognized as agents of util- 



