414 



NA TURE 



[Marc/i 3, 1887 



bably derived form. Instead of being circular in section at 

 right angles to the long axis, they h ere triangular, so that they 

 bore a strong resemblance to the kernels of a beech nut. The 



broad end in this case also was perfectly transparent, and the 

 sharper end banded as before. 



I append three diagrams representing typical forms. 



Ramnagar, Terai, January 25 C. S. Miudlemiss 



Snowflakes 



In your issue of January 20 (p. 271) is an interesting sketch of 

 the snowstorm of January 7, 1887, with mention of snowflakes 

 34 inches long. VVithout vouching for the exact details I send 

 you some statements from a letter in the Nmi York IVorld of to- 

 day's issue. The letter is dated Fort Keogh, Montana, U.S., 

 February 13. " The winter of 1886-87 will be long remembered 

 throughout the north-west for the extreme severity of the tem- 

 perature and the uuu.sual depth of snow. From January 6 to 11 

 the degree of cold was something frightful. Mercury thermo- 

 meters were often congealed, and spirit thermometers were 

 kept jumping from 40° to 60° below zero. Half a dozen times has 

 the 60° notch been touched, and once this season 625° below zero 

 has been scored on the Saskatchewan plains. But the authorities 

 in weather in this country are the Indians. The oldest members 

 of the Crow tribe say there have been few such winters as the 

 present since they settled in the Yellowstone Valley. Curious 

 phenomena sometimes attend a snowstorm. Near Matt. Cole- 

 man's ranch on January 28 the flakes were tremendous, some were 

 larger than milk-pan^. Some flakes measured 15 inches square 

 and 8 inches thick. For miles the ground was covered with such 

 bunches, and they made a remarkable spectacle while falling. A 

 mail-carrier was caught in the same storm and verifies it." The 

 narrative is one of great sufTering, and loss of human lives and 

 cattle. "Miss Maggie Bunn, school-teacher at Highmore, 

 while going from the school to her house was frozen to death. 

 The bodies of three Indians who bel. mged to Berthold Agency 

 were found frozen near Ashland." And so on, in harrowing detail, 

 for a number of whites perished. Samuel Locicwood 



Freehold, New Jersey, U.S.A., February 14 



'Invisible at Greenwich" 



' I WRITE to note an apparent oversight which I have detected 

 in the Nautical Almanac for 1888. The partial solar eclipse of 

 August 7 is stated to be "invisible at Greenwich," but on 

 applying a rigorous calculation I find that it will be visible there 

 to a small extent, the times of contact being as follows : — 



Angle frotr 



Angle from 



the angles being for the direct image. 



I am aware that this is a very insignificant eclipse, but the 

 greatest attainable accuracy is desirable in our national ephemeris, 

 which, indeed, inserts eclipses much slighter than the above, e.g. 

 the lunar eclipse of November 26, 1890, whose magnitude is 

 only ■002. A. C. Crommelin 



Trinity College. Cambridge, February 15 



Lunar Halos 



Last evening (February 8), about a quarter-past eight o'clock 

 (7Sth meridian time), I saw around the moon a series of coloured 

 rings lying close together. The inner one was two or three 

 diameters of the moon from the moon and j-ed, the next was 

 violet, then red, and finally violet again, this last one being very 

 faint. From their proximity to the mion these rings seem to 

 constitute the coronal, but I am puzzled by the fact that the inner 

 ring was red. Do halos ever occur so close to the moon and 

 without an interval between the two pairs of red and violet 

 rings ? 



February 12. — Since writing to you on the 9th inst. I have 



found that my colleague here. Prof. W. G. Brown, noticed the 

 rings around the moon about half an hour before I saw them. He 

 says the colour nearest the moon was yellow, passing into red 

 outwards, and that immediately following the red was violet, 

 then the colours of the solar spectrum in order from violet to 

 red on the outside. This indicates that the first red was really 

 outside a violet ring which fcr some reason was invisible, and 

 brings the phenomenon properly under difi'raction : in fact, we 

 had a good example of the coronal with the innermost rings 

 wanting. S. T. Moreland 



Washington and Lea University, Lexington, Va., U.S.A. 



The Beetle in Motion 



It'" it can interest Prof. Lloyd Morgan I am in a position to 

 communicate that I have many times observed the progressive 

 movements of insects, spiders, and myriapods. I have not 

 noticed the retardation of hind-legs ; it seems to me that this 

 occurs only in the case of bulky and slow-moving beetles, like 

 the larger Melasomata. In general, I find that the mode of 

 progression in articulates does not differ essentially from what 

 we see in vertebrates ; the process is only, at first sight, a little 

 obscured by the plurality of the legs. If we consider only the 

 prothoracic ring of a beetle, we find that it walks like all bipeds, 

 alternating one leg with another. Two segments walk in the 

 manner of quadrupeds, which are not amblers. Now the legs 

 of the third segment must necessarily repeat the movements of 

 the legs of the first segment, for the sake of equilibrium. The 

 fourth ring would repeat the movements of the second, and so on. 



Tashkend A. WlLKlNS 



A Recently-Discovered Deposit of Celestine 

 With reference to Mr. Madan's letter (p. 391), on "A 

 Recently-Discovered Deposit of Celestine," I beg to inform him 

 that a note was read by me at the last meeting of the Mineralo- 

 gical Society, describing these crystals as exhibiting a habit and 

 size unknown till then to occur with such crystals of celestine 

 in England. I obtained the crystals at Christmas, from Mr. 

 Henson, of the Strand, and am expecting to receive more mate- 

 rial, which I hope to work on at the end of Term ; but, unlike 

 Mr. Madan, I have at present been unable to visit the locality 

 where they are found. R. H. Solly 



Mineialogical Museum, Cambridge, February 28 



The Vitality of Seeds 



May I ask, through the columns of your widely-circulated 

 paper, whether there is any really trustworthy evidence for the 

 following statement made by Prof. Judd in his address to the 

 Geological Association (p. 393 in your last issue) : " The botariist 

 cites the germination of seeds, taken from ancient Egyptian 

 tombs, as a striking illustration of how long life may remain 

 dormant in the vegetable world." I know that this is a popular 

 belief, but should like to learn upon what foundation it rests. 

 Probably it would interest other botanists besides. 



February 26 N. E. P. 



THE RELATIONS BETWEEN GEOLOGY AND 



THE MLNERALOGICAL SCIENCES^ 



II. 



LET us now turn from the statical aspect of minerals, 

 their morphology, to the dynamical aspects, their 

 physiology. 



Minerals are not fixed and unchangeable entities, as 

 they are sometimes regarded. On the contrary, they 

 exhibit varying degrees of instability, and pass through 

 very definite series of metamorphoses. 



We have already seen that every alteration in the tem- 

 perature or other' conditions which surround a crystal 

 leads to striking modifications of molecular structure, 

 which are at once revealed by the delicate tests of optical 

 analysis. So sensitive, indeed, are some crystals to the 

 action of external forces, that even the passage of the 



■ Address to the Geological Society at the .•\nniversary Meeting on 

 Februar>' 18. by the President, Prof. John W. Judil, F.R.S. Continued 

 from p 396. 



