126 



KNOWLEDGE & SCIENTIFIC NEWS. 



[June, 1904. 



explains, to the fact that an adult tree of the Hcvca " puts forth 

 fresh foliage annually, and the bud-scales being caducous, 

 are merely evident while the shoots are in the immature con- 

 dition." The honey secreted by the nectaries encourages the 

 visits of ants, whose presence assists in safeguarding the 

 developing foliage from the attacks of injurious insects. 



PHYSICAL. 



The Emanation from Radi\im Bromide. 



Til show the diltusion of the cuianation from radium bro" 

 niide. Mr. T. Indricson, in a paper recently read before the 

 Russian Physico-Chemic.al Society, used a long tube, the in- 

 ternal surface of which was coated with a layer of zinc- 

 sulphide. On connecting the apparatus with a test-tube 

 containing a solution of radium bromide, luminescence was 

 found to appear and to be prop.agated throughout tlie tube. 

 On rcpc.iting Ramsay's experiments, the author found that 

 the yellow helium line did not coincide with the yellow lines of 

 the spectrum given by the emanation, but was situated between 

 the two yellow lines of the emanation. When the serpentine 

 coil conununicating with the tube was dipped into lir|uid air. a 

 strengthening of the lines corresponding to the helium line was 

 noted in the spectrum of the emanation, while between the 

 two yellow lines above referred to a third line, coinciding with 

 the yellow line of helium, appe.ai-ed. The lines of helium do 

 not exist in the spectrum given by the emanation of a freshly- 

 prepared tube, but only appear afterwards. On observing the 

 gases set free on the dissolution of radium bromide, it was 

 observed that the helium lines did not appear as long as the 

 spectrum tube preserved its phosphorescence in the dark. 

 After four days this phosphorescence would disappear, and the 

 lines of helium could be noted in the spectrum. — A. G. 

 * * * 



Action of Ratdium on Metals. 



In order to investigate the action of radium on metals, 

 N. Orloff, as pointed out in a paper recently read before the 

 Russian Fhysico-Chemical Society, covered, in April, 1903. an 

 ebonite capsule containing 0-03 gm. of radium bromide with 

 an aluminium plate o'oi mm. thick, instead of the mica gene- 

 rally used. In the course of July the author, on opening the 

 capsule, noted on the surface of the aluminium turned 

 towards the radium some protuberances of the same aspect 

 as the surrounding surface of the aluminium, and resembling 

 small drops of melted metal. These protuberances proved to 

 be radio-active, producing a photographic image on acting for 

 some minutes through bl.ack paper : and even after six months 

 they were found to emit invisible radiation without any appre- 

 ciable weakening. The author thinks that a stable alloy is 

 formed by the accumulation of material particles given off 

 from the atomic systems of radium, around small aluminium 

 nuclei. — A. G. 



•* ■» * 



On Radio-Active Ennanation from 

 Water and Oil Fountains. 



In a paper published in No. S of the Physikalischc Zcitschrijt 

 (April 15, 1904), Prof. F. Himstedt arrives at the conclusion 

 that radio-active bodies giving off a gaseous emanation are 

 widely diffused throughout the earth ; these emanations are 

 absorbed by water or by petroleum, and after having been 

 conveyed along with the latter to the surface of the earth, will 

 thence diffuse into the air. Because of the many analogies 

 noted between these emanations and radium emanations, the 

 author thinks it possible that both are identical. In this case 

 the ores of uranium, from which radium emanations are de- 

 rived, would either be widely diffused or else there would be 

 some further matters possessing, though to a lesser degree, the 

 property of giving off emanations. Considering that the ab- 

 sorption coefficient of water, as well as of petroleum, with 

 respect to this emanation, is found to decrease for increasing 

 temperatures, while hot fountains, on the other hand, show an 

 especially high activity, the hypothesis is suggested that the 

 amount of radio-active mineral increases with increasing 

 depth. The radio-active components of the earth should, 

 therefore, possibly be allowed for in estimating the tempera- 

 ture of the earth's mass. — A G. 



ORNITHOLOGICAL. 



By W. P. PvcRAFT, A.L.S., F.2.S., M.B.O.U.,&c. 



Gloss ylbis in the Orkneys. 



The "Annals of Scottish Xatnnil History " for May contains an 

 account of a Glossy Ibis, Ibis Jnlcindlus, shot a mile west of 

 Stromness on September 19 last. According to Mr. Eagle 

 Clarke this is only the second occurrence of this bird in the 

 British Islands, the first having been shot in iSjy near Kirk- 

 wall. Some mistake has certainly been made here; for which 

 Mr. Eagle Clarke can hardl\- be responsible. So good an 

 ornithologist doubtless knows that at least thirteen instances 

 of its occurrence in Great Britain are recorded, one of these 

 being from .Vberdeen-shire — October 4, 1880. According to 

 Mr. Ussher there are no less than twenty-two instances of its 

 occurrence in Ireland. 



* * •* 



Rough-Legged Buzzard in Co. Down. 



The Rough-legged Buzzard. iUitm tiii^opns. is only a rare 

 visitor to Ireland. According to the Irish iS'iitnralist (May) 

 a specimen v/as shot in November last in Co. Down — 

 the fifth in Down. This appears to be the tenth recorded 

 instance of its occurrence in Irish territory. 



Stone-Curlew: Co. Donegal. 



An example of this rare visitor to Ireland was obtained on 

 < )ctober 12 last in Co. Donegal. This is the first time of its 

 occurrence in Donegal. Only ten other cases of its occurrence 

 in Ireland are on record, and eight of these, it is interesting 

 to note, were obtained on the East Co.ast. 



* * * 



Ravens Nesting in Captivity. 



Instances of ravens breeding in captivity are rare; and 

 cases of successful rearing are still more so. Mr. W. H. 

 St. Quintin's note in the Field (May 7) to the effect that he has 

 in his aviary a pair of young that are nearly ready to leave the 

 nest is therefore of considerable interest, especially so having 

 regard to a certain police court prosecution which took place 

 some time ago. 



* * * 



Great Crested Grebes at Richmond. 



Mr. Gordon Dalgliesh sends us some interesting notes on a 

 pair of these birds which he has had under observation since 

 April 17 last. They have taken up their quarters in the Penn 

 Ponds and appear to be breeding. When preening the breast 

 feathers, he remarks, these birds turn over on to their backs 

 and do not perform this operation when sitting upright as one 

 would imagine. " The female, when she landed, did not stand 

 upright, but dragged herself along on her belly." 



Colour, and Coloration in Birds. 



An extremely interesting and important paper on this sub- 

 ject was read by Mr. T. Lewis Bonboteat the Linnean Society 

 on Ma}- 5, to which we hope to be able to refer later. 

 Briefly, he contends that bo;h colour and coloration are prim- 

 arily due to physiological causes, and that the varied patterns 

 and tmts of plumage which distinguish different species are 

 determined by the action of natural selection on these " ex- 

 pression points " of "vigour." 



There is an intimate connection, he contends, between the 

 bleaching process which takes place previous to moulting, and 

 the development of conspicuously marked areas. These in- 

 deed, he holds, are nothing more than permanently fixed 

 bleaching, or intensification areas, which he terms " pitcilo- 

 meres." 



Messrs. Newton and Co., who have held appointments to 

 the Royal Family continuously since i860, have this week 

 been honoured by a Warrant of Appointment as Scientific 

 Instrument Makers to H.R.H. the Prince of Wales. 



