500 



NATURE 



{April 7 f^, 1872 



ought to experience the least difficulty in using the simple adjec- 

 tives "higher" or "upper" and "lower" for the parts of the 

 spectrum, and the simple prepositions "above" and "below," 

 where required. There is no possibility of misconception, and 

 no explanation is needed. 



Probably we have got beyond the stage in which misconcep- 

 tion is likely to arise froati the careless use of words expressing 

 continuity or otherwise in a spectrum ; but I would suggest the 

 word "diffuse" where it is not intended to express anything 

 precise. Thus the coronal spectrum is diffuse until we know it 

 to be solar. M. Janssen testifies to dark lines seen in the (diffuse) 

 spectrum, J. Herschei, 



Camp Nandair, Hyderabad, March 19 



Turner's Vision 



I HAVE been waiting since the appearance of a report of Dr. 

 Liebreich's lecture in Nature of March 21 expecting that an 

 animated discussion would be provoked, affording me an oppor- 

 tunity of slipping in obscurely as a minor combatant, the subject 

 being one on which I am but veryindifferentlyqualified tospeak, 

 although thirteen years ago I did incidentally suggest an explana- 

 tion of the pecuiiirities of Turner's later pictures which, simple 

 as it is, still appears to me sufficient. On page 67 of " Through 

 Norway with a Knapsack," published in 1859, speaking of some 

 of the peculiar midnight sunset effects of the North, I said that 

 "Turner, like an eagle, has dared to face the sun in his full 

 glare, and to place him in the middle of his pictures, showing us 

 how we see a landscape with sun-dazzled eyes, when everything 

 is melted into a luminous chaos, and all the details blotted out 

 with misty brightness." 



In all these peculiar pictures that I have seen the sun is thus 

 placed in the middle of the picture, and just sufhciently above the 

 horizon (from about 10° to 20', or at most 25°) to pour his rays 

 about perpendicularly to the curvature of the eye-ball, when the 

 face is in position to contemplate a landscape. I have frequently 

 repeated the experiment of contemplating a landscape under such 

 circumstances, and on every occasion of submitting to such tor- 

 ture have seen all the effects of even the most extravagant of 

 Turner's later pictures, which are so well described by Dr. 

 Liebreich. I have seen the "vertical streakiness, which is 

 caused by every illuminated point having been changed into a 

 vertical line," with an "elongation, generally speaking, in exact 

 proportion to the brightness of the light," and that "there pro- 

 ceeds from the sun, in the centre of the picture, a vertical yellow 

 streak." These appearances may arise from an affection of the 

 crystalline lens of my eye similar to that attributed by Dr. 

 Liebreich to Turner, or it may be due to something else much 

 simpler, and which is more or less common to all human eyes. 

 If the simpler explanation based upon normal conditions covers 

 the facts, it certainly must be the more acceptable. 



My explanation of the vertical streaks is this. When we thus 

 look full faced at the sun, the dazzle produces slight inflammation 

 or irritation, and a flow of tears. The liquid accumulates, and 

 rests upon the lower eyelid, forming a little pool, the surface of 

 which has a considerable vertical curvature, i.e. the lower part of 

 the retained tear curves upwards from the surface of its base at 

 the root of the lower eyelashes to its summit contact with the 

 conjunctiva. Thus in a vertical direction it must act as a lens of 

 very short focus, it must refract and converge the rays of light in 

 a verticil plane, and thus produce a vertical magnifying effect, 

 the definition of which will of course be very confused and ob- 

 scure, on account of the irregular curvature, and the fact that the 

 eye is focused to the distant objects. This want of directive 

 focusing will limit the distortion to the bright objects whose verti- 

 cally magnified images will be forced upon the attention. 



To test this explanation let any one select a bright afternoon, 

 and at about 6 p. M. or a little later, at this season, gaze sunward 

 upon any landscape free from London smoke or other medium of 

 solar obscuration. At first, if his eyes are not very sensitive, he 

 will see a circular sun, but presently, as the tears accumulate, 

 the vertical elongation of the sun and general " vertical streaki- 

 ness" will appear. When I tried the experiment last week the sun 

 appeared like a comet with abrilliant vertical conical tail, the point 

 of which rested on the horizon. But I was then slightly troubled 

 with what is called "a cold in the head," and my ey^s watered 

 very vigorously, and thus the conditions for producing fine 

 Turneres:|ue effects were highly favourable. On carefully dry- 

 ing my eyes these effects were, for a moment, considerably 

 diminished. 



I have adopted another method of testing this explanation. 

 Having caused the eyes to become somewhat suffused, I bring 

 the upper and lower eyelids so near together that the liquid shall 

 occupy a sensible depth, i.e., from the conjunctiva to the base of 

 both upprrand lower eyelashes, and by compression be bulged 

 or curved outwards in the vertical direction. On looking 

 through this tear-filled chink at a gaslight, the vertical elonga- 

 tion is remirkably displayed, and it extends upwards or down- 

 wards or both according to the position of the liquid. When 

 looking at the sun and landscape with the eyes fully opened 

 (which i; very painful), the elongation is chiefly down v.irds, 

 and obviously connected with the tear on the lower eyelid ; but 

 if the eyelids be nearly closed to diminish the intensity of the 

 light, an upward elongation is also commonly visible. 



The other phenomena represented by Turner are, I think, 

 simply a faithful copying of the effects of glare and suffusion 

 produced by painful sun-gazing and the looking at a landscape 

 where the shadows are, so to speak, nowhere, or all behind 

 one's back. W. Mattieu Williams 



The Adamites 



As " M. A. I." prefers to keep his incognito, I shall not seek 

 further to induce him to reveal himself. He has now, however, 

 pointed out what he conceives to be errors in my paper, and I 

 will reply to his criticism. 



In the first place, as to the word pi-tci, I neither said nor inferred 

 that the final syllable is not a suffix. My remark was that it 

 retained a primitive root, ta, which is found al^o in the Semitic 

 'ata, and I submit still that I am perfectly correct. The suffix 

 tar in Sanskrit denotes nouns of agency, as Bopp shows in his 

 " Comparative Grammar," and I am quite justified, when I find 

 in various other languages a root word similar both in sound and 

 sense, in inferring that the Sanskrit suffix was originally of the 

 same character. I have hitherto been under the impression that 

 comparative philology had established that suffixes were at one 

 time independent words, but it appears that I am wrong. To 

 show, however, that I have erred in good company, I would refer 

 to Prof. Max Muller's "Stratification of Language" (p. 32), 

 where it is said, " suffixes and affixes were all independent words, 

 nominal, verbal, or pronominal ; there is, in fact, nothing in 

 language that is now empty, or dead, or formal, tli.at was not 

 originally full, and alive, and material." I must plead guilty of 

 ignorance of " M. A. I. 's" scientific method. 



As to Tiiala, when it is shown that Ta:}iata or Taiigata was 

 the original form of the Polynesian deity's name, I shall be 

 better able to reply to your correspondent's criticism. In any 

 case, the final syllable is evidently the word denoting "spirit," 

 and I see no difficulty in Ta becoming either Tarn or Tang as 

 the result of phonetic change. The mere fact that Taata and 

 Tiki 3.K different gods with different attributes really amounts to 

 nothing, since such a division of personality and characteristics 

 is a common fate of the divinities of heathen mythologies. I see 

 no reason to change my opinion that the name of the Polynesian 

 great ancestor has preserved the same primitive root as that which 

 is to be found in the name of the first man, Adam, of the Semites, or 

 rather of the A/;/:a / forerunners. 



While replying to " M. A. I.," it may be well to notice the 

 criticism of his advocate, Mr. Jenkins, for whose explanation 

 of the meaning of the word Adam I am much obliged, 

 although, if he will take the trouble to read my paper, he 

 will see that I was not ignorant of what he states. But the 

 acceptance of the Hebrew meaning of the word as the 

 original one does not lead me to place much reliance on Mr. 

 Jenkins's judgment. If the Old Testament narrative proves any- 

 thing beyond a knowledge of the tradition as to Adam, it is that 

 the narrator was a bad philologist, and that finding the Hebrew 

 word adainah, he forthwith inferred that the first man was made 

 of ground-dust, which give to him its red colour. For my p.art, 

 I entirely ignore the authority on such a point of the Hebrew 

 writer, and in justific.Uion I beg to refer to the statement made by 

 the Rev. A. H. Sayce before the Society of Biblical Archrcology, 

 as reported in the last number of Nature (p. 495), that the 

 early Semitic traditions are derived from an Akk.adian source, as 

 are also most of the biliteral roots of the Semitic language. If 

 the traditions are taken from that source, the probability°is that 

 the proper names they enshrine have had the same origin ; and I 

 subinit, therefore, tliat I am quite justified in tracing the meaning 

 of the word Adam to the old Chaldean tongue, in which, as Mr. 

 Norris's Assyrian dictionary shows, and as my paper asserts, Ad 

 signifies "a father." 



