444 



NATURE 



{April A,, 1872 



Sf.EiNG your account of the aurora of February 4 in Nature 

 of the 22ncl, lemincls me that on the evtni-.g ut tne 4th I was 

 ridinc fiom Cambridge to Coldwell, in Ohio, and between iix 

 and seven o'clock saw a most brilliant dis^jlay of auroral light in 

 the southern quarter of the sky. Brilliant streamers shot up 

 pa?t the zenith, while the whole southern portion of the sky was 

 brightly illuminated with a corruscating rose-coloured light. 



Marietta, Ohio., March 15 A. J. Warner 



Morse on Terebratulina 



I HAVE just read the very kind notice of my paper* in the 

 p.iges of your journal from the pen of Mr. L. R. Lankester. 

 1 hasten, however, to remove one impression conveyed in the 

 following sentence, respecting the opinions I hold as to the Anne- 

 lidjn affinitiei of the Bmchiopods: — 



" We aie not sure whether Mr. Morse adheres to this startling 

 proposition." 



I tnist the long delay in publishing the results of my studies 

 on this interesting class will lead no one to suppose that I have 

 yet seen reason to modify the position I took two years ago re- 

 garding their position in the animal kingdom. On the contrary, 

 continued investigation has brought out many new points of in- 

 terest, and now 1 hope, ere my paper is published, to present the 

 embryology of some one of them. 



I had studied our native Terebratulina, its structure, as well 

 as its early stages, and through the kindness of Prof. Verrill, 

 had studied Discina hrvis (upcn which I hope soon to publish). 



Mr. Lankester, as the author of many valuable memoirs re- 

 quiring much skill and patient labour, will fully appreciate the 

 time and care necessary in work of this kind. 



As to my being unduly impressed at the sight of living Lin- 

 gular, I may say, in justice to myself, and my friends will testify 

 to it, my opinions were fully formed before I ever saw Lingula 

 at all. With the caution that is requisite for every one, if he 

 does not wish to supplement his paper with a correction of 

 errors, a way of doing things altogether too frequent in this 

 country, I deemed it important to study living Lingula before 

 publishing. It was impossible for me to go half-way round the 

 world for it. And as three specimens of another species have 

 been found on the coast of North Carolina, I determined to go 

 there. A trip of nearly a thousand miles brought me to its 

 waste of drifting sands. 



Thoroughly convinced as to the correctness of my views, and 

 these views of sufficient strength to convince my co-labourers, 

 Mr. Lankester will understand my enthusiasm when, after a 

 week's fruitless search under a blazing sun, and an almost hope- 

 less task, I found Lingula, not as we have always supposed 

 attached by its peduncle, but living in the sand, precisely like 

 many tubicolous worms, build'.ng a true sand tube, and when 

 liberaied from it crawling and burrowing by means of its setce, 

 and with all these welcome characters it should greet me with 

 red blood. Not that I lay great stress on any one of these 

 characters, but having made my deductions from the most com- 

 mon form, Terebratulina, one can readily understand the bearing 

 of such unexpected characters in this little Lingula. 



Mr. Lankester will admit that the Vermian lumber-room has 

 some orderly compartments ; into one of those I place the 

 Brachiopods far away from all Molluscan odours. 



The distinguished naturalist. Prof Sleenstrup, informs me that 

 he h.is long taught his classes at the University of Copenhagen 

 that the Brachiopods were true Annelids, and that my ™ws are 

 thoroughly endorsed by him. To him, therefore, and not to me 

 as had been supposed, belongs the priority of this discovery. 



I oniy ask a little patience till my complete paper is pub- 

 lished on the Brachiopods as a division of Annelida, in which I 

 shall give appropriate figures, and my reasons in full for the 

 position I have taken. EDWARD S. MoRSE 



Salem, Mass., U.S.A., March 14 



On the Colour of a Hydrogen Flame 

 When hydrogen and ox)gen are burned together, it is well 

 known that the flame produced is almost non-luminous ; it 

 always, however, exhibits an unmistakeably blue tinge. 



Tlc small illuminative power is generally referred to the "ab- 

 sence of solid particles." This view, it appears to me, draws a 

 too rigid line of demarcation between the atoms of carbon in an 

 ordinary gas-coal flame and the atoms of hydrogen in that of 



* " Early Stages of Terebratulina." 



the oxyhydrogen. The cause of the phenomenon does not de- 

 pend so much on the soluiity as it does on the time of oscihation 

 of the particles which constitute the flame. Wattr par.icles in 

 all their states of aggregation preserve the same time of oscilla- 

 tion — extra red ; hence a hydrogen flame should be perfectly 

 invisible whatever may be the " solidity " or density of its 

 particles. 



But the flame is not invisible, and, what is still more remark- 

 able, the colour which it does exhibit is found to belong to the 

 most refrangible end of the spectrum. To explain this sttange 

 phenomenon, it appears to me that it is necessary to invoke a 

 state in the ether particles similar to that which lielmholiz has 

 shown to exist in air ; and which is this : — A tuning-fork 

 " vigorously struck against a pad emits the aAzrf of its funda- 

 mental note." Now, the first overtone of a tuning fork is pro- 

 duced by vibrations about 6J times as rapid as the fundamental ; 

 the octave, therefore, is not an overtone of ttie fork — it is pro- 

 duced solely in consequence of the fact that the initial distur- 

 bance is great in proportion to the distance of the air particles 

 from one another, secondary waves being produced whose periods 

 are twice as rapid as those of the fundamental. 



The amplitude of the particles in a hydrogen flame is known 

 to be very great, and hence it seems probable that an effect may 

 result from the disturbance thus created in the eJier, analogous 

 to that in the case of air, i.e., associated with the fundamental 

 vibrations of the hydrogen flame we have their octave, which 

 would obviously ..be within the visual range, and correspond very 

 cloz-ely, if not cxact'y, with the colour actually observed. 



Should this surmise prove correct we have plainly an easy 

 means by which we can determine the wave-length of those 

 extra-red rays which are absorbed by water. 



A. G. Meeze 



Hartley Institution, Southampton, March 26 



P.S. — May not the great actinic power of the electric light be 

 due in a great measure to the secondary waves produced by the 

 magnitude of the disturbing force ? 



VESTIGES OF THE GLACIAL PERIOD IN 

 NORTH-EASTERN ANATOLIA 



ATTENTION was drawn to this subject in a lec- 

 ture given on March 25 at the Royal Geographical 

 Society by the Eastern traveller Mr. W. Gifford Palgrave, 

 at present British Consul for the northern coast ol Asia 

 Minor. The facts which he mentioned had been princi- 

 pally observed by him during a tour on duty to the interior 

 about two years ago ; and the line of route lay from the 

 town of Trebizond on the sea coast to that of Erzinghian 

 on the Upper Euphrates. 



The phenomena themselves were divided into two 

 classes : the one referable to the highlands which he had 

 then traversed, the other to their marginal region. 



These highlands are situated on or near the 40th 

 parallel of latitude, and extend between the 37th and 44th 

 of longitude, east and west ; their average breadth being 

 about fifty miles, and their elevation varying from 3,000 to 

 9,000 feet above the sea. They constitute the great 

 watershed of Eastern Anatolia ; the rivers to the south 

 of them flowing into the Persian Gulf, and those to the 

 north into the Black Sea. To the west is the basin of 

 the Halys, to the east that of the Caspian. 



The road leading across this plateau towards Erzinghian, 

 mounts up to it by a defiie named " Ketcheh-Dereh," or 

 " Goats' \'alley." Here, at a height of about 5,400 feet 

 above the sea, Mr. Palgrave came on the lower extremity 

 of a large moraine, piled up to a height of more than 

 twenty leet, and bioad in proportion. Following it for a 

 distance of nearly half a mile, he found that when it had 

 reached between 400 and 500 feet higher up the slope, it 

 forked into two lesser branches, continued each a good 

 way further into the rising undulations of the table-land. 



The plateau itself bore every mark of having lain under 

 a thick ice-coating ; its eminences and irregularities all 

 bearing the '"moutonnde" character impressed by glacia. 

 action ; while it was also frequently strewn with detached 



