348 



• KNOWLEDGE • 



[Oct. 24, 1884. 



=^=^^s«s^-i5n>; 



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MIND AND BRAIN. 



[1467] — I see that your correspondent, "F. W. H.," "in the 

 interest of trnth only," has attempted an answer to the query 

 which I put in my former letter. In the same interest, I could 

 have wished that the answer were more satisfactory, and more to 

 the point. For where, I ask, lies any true analogy between the 

 purely mechanical action of light waves passing through a prism, 

 so producing colour, and the production of intangible thought from 

 the brain by the conscious effort of the human will ? Such similes 

 are, almost, proverbially dangerous and misleading. "F. W. H." 

 has entirely missed my point. If his comparison has any bearing 

 whatever upon the subject, the lecture which he supposes, on 

 geology, or astronomy, or theology, might be likened to the ray of 

 light which, being brought to bear upon the prism of the brain, 

 produces certain differently colom-ed thoughts, so to say, 

 in its passage through the brain of the hearer. Bnt my 

 question is, whence come the stimuli when the force of ex- 

 traneous circumstances fails to account for them ? Whence 

 comes the power, which, in the form of will, uses the brain as its 

 instrument, and compels it, without any assistance from external 

 surroundings, to vibrate in such a manner as to do the particular 

 work, to produce or evolve the special chain of thought which I 

 will it to do ? Whence, in a word, arises this dominating power of 

 will over the vibrations of the brain in the production of thought? 

 The letter of F. W. H. has thrown no light whatever upon this 

 question. S. F. B. Peppin. 



Does the thought produce the vibration of the brain, or does the 

 vibration of the brain produce the thought ? 



WOLF'S COMET. 

 [1468] — During a short interval of clear sky, I picked up the 

 new comet last night in my 2J-inch. It is conveniently near £ 

 Pegasi now, and appears like a nebulous patch. A. N. S. 



[1469]— I obtained a good view of this object last night. With 

 6-in. reflector it appeared as a slightly elongated nebulosity with 

 central cx)ndensation, and perhaps just a suggestion of a tail. 

 Determining its position from i Pegasi, I found it approximately 

 R.A. 21° 33' (N.B., 12° 26', instead of 12° 5' as given in the 

 Dunecht circular quoted in Knowledge). The declination was 

 corrected for the time given, viz., llh. 6m. p.m., and is, I feel sure, 

 correct within an outside error of 2'. E. S. Beaven. 



Warminster, Oct. 12, 1884. 



SHOOTING STABS AND METEOES. 



[1470] — Mr. W. H. S. Monck seems to misunderstand my letter 

 (1405). 



I did not say that under the conditions alluded to the orbits of 

 t he shooting stars would not be altered ; on the contrary, I believe 

 they would. I only submitted on ocular grounds that the earth 

 could not be their centre. 



I think it is generally supposed that the great bulk of meteors 

 which enter the earth's atmosjjhere, after disintegration by vapori- 

 sation, solidify in the form of dust, and so imperceptibly reach the 

 earth's surface, while a small remainder, undergoing a trifling dis- 

 integration fall in a soUd heated mass as aerolites. Eye-\vitxess. j 



INFLUENCE OF MOONLIGHT. 



[1471] — As I can speak from personal experience, I shall have 

 much pleasure in giving you my opinion uijon the subject. When 

 a youngster, twenty years ago, I had the same impression as your 

 correspondent's friend had, and implicitly believed that sleeping 

 under the direct rays of the moon caused blindness, and I remem- 

 ber reading of a girl that, I believe, quarrelled with her parents 

 and slept in a corn-field all night, and it was said that she became 

 blind, during the night, from the action of the rays of the moon, 

 but I cannot vouch for the truth of it . My opinion was completely 

 modified when I was forced, from too much company in my bunk 

 (of the heavy dragoon tribe), to seek rest on deck for six weeks, 

 whilst the ship I was in was at Hong-Kong and Foo-Chow (I was 

 a sailor then), and I remember I used to try to get where the moon 

 did not shine upon me fair, but I never conld, for what with the 

 swinging of the ship and course of the moon, I repeatedly awoke 

 with the moon shining full in my face, and suffered no ill-effects of 

 the same. My opinion is that, if the sleeper has his eyes closed, 

 no harm will come to him ; but, if in the habit of sleeping with his 

 eyes open or partially open, then the rays of the moon may have an 

 injurious effect, for the bright light in Egjpt causes ophthalmia. I 

 can say nothing about the fish not keeping. I may mention that 

 the dew fell very heavily, and that nearly all the crew slept on 

 deck, but not one that I knew was affected. — I remain, dear sir, 

 yours truly, K. J. Symonds. 



[1472] — In reply to the {|uestion of yonr correspondent at p. 305, 

 as to the influence of moonlight, it is one to which I have given my 

 attention as a medical man, resident in India over twenty years, 

 and during several voyages there and back. I have never been able 

 to make out that the light of the moon had any influence whatever, 

 but came to the conclusion that all the evil effects attributed to it 

 arose from muscular rheumatic affections produced by sleeping — 

 not in the moonlight — but in a draught or cold air. Sailors who, 

 after a hot day in the tropics, lie down to sleep with their heads in 

 an open port, are subject to attacks of the kind, and if the moon 

 should have happened to shine in on their faces they attribute all 

 the results to it, instead of to the effect of the cold air. What is 

 called in the tropics moon-blindness, is quite a different matter. 

 This occurs among weakly and badly-fed natives from other very 

 obvious causes, and is a weak condition of the eye, which prevents 

 them seeing well after dnsk. B. M., F.H.C.S. 



THE ECLIPSE OF THE MOON. 



[1473] — In reference to your remarks in " Editorial Gossip," in 

 your last number, on your own observation of the lunar eclipse, 

 permit me to state I observed the same phenomenon, excepting the 

 green-tinted ring. I did not observe the ingress, being engaged 

 within doors. A friend entered and said the eclipse was total. I 

 immediately went out and found that my friend did not clearly dis- 

 tinguish the difference betwixt umbra and penitinbra, which I never 

 before saw so clearly defined. Just before totality I again went 

 into my room, not staying there more than two or three minutes, 

 when, on returning to the garden, I had some difficulty in finding 

 the exact place of the moon, so thoroughly was she obscured — any 

 trace of light was absent. 1 have previously observed during an 

 eclipse the moon's peculiar hue, but on this occasion I could not see 

 the dark body of the moon without considerable effort. The skies 

 were cloudless. 



During egress, I could well observe that the diameter of shadow 

 was much larger than the diameter of moon, but when about six- 

 tenths of moon's disc only was in shadow, the segment of moon's 

 bright side did not appear as any part of a circle, but rather of a 

 parabolic curve. 



Was this appearance an optical illusion, or was it more likely to 

 arise from defective vision ? Pardon my intrusion. 



William J. Daties. 



[The moon's diameter may be taken to be 2,160 miles ; that of 

 the earth's shadow at the moon's distance from us on the night of 

 the 1th, as 5,879 miles. Does Mr. Davies mean that the moon's 

 limb or the edge of the shadow on her surface showed parabolic 

 curvature ? — Ed.J 



EXPOSITORY THOUGHTS ON THE CREATION. 



[1474] — I have read the very tmfair and indiscriminate critical 

 notice of this my book, in your number of August 29 last, and in 

 common justice to me I hope yon will be kind enough to insert this 

 letter in answer thereto, in an early issue of your periodical. 



Passing by yonr general summary of the work as " hopeless non- 

 sense," as scurrilous in the extreme, to say the least of it, I beg to 

 Bay that I do not in my preface " deprecate adverse criticism on the 



