February i8, 1892 



NATURE 



379 



greater number of cases occurred just before a thaw. The most 

 common type of cloud which preceded both cyclonic and anti- 

 cyclonic cases of silver thaw was cirro-cumulus, frequently 

 accompanied by cirrus and cirro-stratus ; and the changes showed 

 that the higher strata of the atmosphere came first under the 

 influence of the moist current, which took from three to eight 

 hours to descend to the height at which cumulo-stratus forms. 

 An examination of a series of storm charts prepared by Dr. 

 Buchan disclosed the somewhat remarkable fact that 73 per 

 cent, of the cyclonic, and 63 per cent, of the anticyclonic cases 

 of silver thaw on Ben Nevis were followed or preceded by gales 

 on our northern and north-western coasts ; and it would appear 

 from the wind conditions that the barometric gradient at the 

 height of Ben Nevis (4407 feel) must be totally different from 

 what obtained at sea-level during the occurrence of silver thaw 

 on the hill-top. Many of our readers will remember the re- 

 markable case of silver thaw which occurred in London last 

 Christmas Day. 



There has been much talk in Germany about Dr. Peters's 

 discovery of saltpetre in the Kilima Njaro district. This dis- 

 covery accords with statements which were already well known. 

 Dr. Fischer, after an examination of the Donjongai volcano, 

 reported that in the neighbourhood of the crater there were a 

 series of curiously shaped veins of a white substance which he 

 took to be either saltpetre or soda. In 1879, Herr Jarler 

 asserted that large quantities of sulphur would probably be 

 found in the crater. The Berlin correspondent of the Times, by 

 whom these facts are noted, adds that not far from the volcano 

 there lie great swamps from which soda is obtained. It is ex- 

 pected that an expedition for the exploration of the district will 

 soon be sent out by the German East Africa C6mpany. 



Prof. A. Giard calls the attention of naturalists to a new 

 case of mimicry between two very different insects (the one 

 Hymenopterous, the other Dipterous)— .,4/-^a/?(a: anmtlata and 

 Beris vallata. When both insects are quiet, the resemblance of 

 colour and patterns is perfect, and as the Athalia, like most 

 Tenthrediuce, is protected against birds and other foes by its un- 

 pleasant smell, it is probable that the resemblance is of con- 

 siderable service to Beris. M. Giard also refers to the larva of 

 Allantus tricinctus which is commonly found on the leaves of 

 plants, vividly coloured, and quite conspicuous, but resembling 

 in form and colour birds' droppings, as is the case with a spider 

 described by H. O. Forbes. 



The number of persons who approve of cremation seems to 

 be steadily increasing. From the Report of the Cremation 

 Society of England for 1891, we learn that in 1885, the first 

 year the crematorium at Woking was used, only three bodies 

 were sent there ; in 1886 the number was 10 ; in 1887, 13 ; 

 in 1888, 28; in 1889, 46 ; in 1890, 54; and during the past 

 year, 99. Crematoria are being built in various parts of the 

 country. At Manchester a crematorium is in course of erection, 

 and will, it is thought, be completed and opened for use during 

 the coming spring. A company has also been formed, and is 

 making rapid progress, with the same object at Liverpool ; and 

 the City of London Commission of Sewers is taking steps 

 to obtain powers to erect a crematorium at their cemetery at 

 Ilford. The Cremation Society at Darlington, and other 

 associations, are moving in the same direction. 



A SMALL axe of nephrite, found at Ohlau, in Silesia, and 

 now in the Roman-German Museum at Mainz, has lately been 

 carefully examined by Dr. O. Schoetensack, with a view to the 

 discovery of the source from which the material must have been 

 obtained. From a thorough determination of its specific 

 gravity, microscopic structure, and chemical composition, Dr. 

 Schoetensack concludes that the nephrite is exactly the same as 

 NO. II 64, VOL. 45] 



a mineral which has been found by Dr. Traube near Jordansmiihl, 

 in Silesia. There is no reason, therefore, why the axe should 

 not be pronounced to be of Silesian origin. This is the only 

 prehistoric object of nephrite, found in Europe, the source of 

 which has been definitely decided. 



Probably few authorities responsible for the making and 

 maintenance of roads are aware that one of the things against 

 which they should be on their guard is the use of rotten flints 

 for macadamising purposes. Mr. C. Carus- Wilson has been 

 giving some attention to this subject at Bournemouth, and, in a 

 letter to a local journal, states the conclusions at which he has 

 arrived. He was led to consider the matter by the abnormal 

 quantity of slush on the surface of Poole Road. This he attri- 

 butes to the fact that the road has again and again been mended 

 with rotten flints, by which he means flints that have become 

 decomposed to such an extent that there is very little true flint 

 left. These flints are surrounded by a thick zone of soft white 

 material. This is rapidly removed from the flinty nucleui by 

 the grinding and pressure to which it is subjected ; while the 

 true flinty nucleus, being thus denuded of its outer covering, 

 becomes too small to bear much crushing weight, so that it 

 quickly breaks up, and forms a fine flint sand. Mr. Carus- 

 Wilson has found by repeated microscopic analysis that the 

 Poole Road mud is formed principally of these two substances. 



The Journal of the Society of Arts prints this week an 

 interesting lecture on burning oils for lighthouses and lightships, 

 by E. Price Edwards. It was delivered at a meeting of 

 the Society on February 10. After the lecture Sir Lyon Play- 

 fair, who was in the chair, said it was quite clear that mineral 

 oils must in time beat the vegetable oils, on account of their 

 chemical composition, the ingredients in the latter not being all 

 combustible, but consisting of fatty acids and glycerine. 

 Mineral oils, on the other hand, were nearly of the same 

 composition as olefiant gas, the illuminating constituent of 

 coal gas, with the addition of a little more hydrogen. They 

 were therefore sure to win in the end ; it was merely a question 

 of manufacturing them safely. 



At the meeting of the Field Naturalists' Club of Victoria on 

 December 14 last, Mr. A. J. Campbell read a paper on a nest 

 and egg of a bird of paradise {Pliloris victoria). Eastern 

 Australia possesses a genus (three species) of these beautiful 

 birds, but they are very seldom seen. The nest was found on 

 November 19, by Mr. Dudley Le Souef and Mr. H. Barnard 

 during a visit to the North Barnard Islands, about forty miles off 

 the coast from Cardwell, Queensland. They watched the hen 

 bird for some time, and saw her fly into the crown of a Pan- 

 danus tree growing close to the open beach. Although they 

 could not distinguish the nest itself, they could see the head of 

 the bird as she sat on it. The nest was about 10 feet from the 

 ground, and the bird sat quietly, although they were camped 

 about 5 feet away from the tree. There was a single egg, the 

 incubation of which was probably about seven days old. The 

 nest was somewhat loosely constructed of broad dead leaves and 

 green branchlets of climbing plants and fibrous material. In- 

 side were two large concave-shaped dead leaves underneath 

 pieces of dry tendrils which formed a springy lining for the egg 

 or young to rest upon. The following is the measurement in 

 centimetres : over all, 19 broad by 9 deep ; egg cavity, 9 across 

 the mouth by 4 deep. 



Dove's observation that when a tuning-fork of proper pitch is 

 held to each ear beats can be heard, where there is no possi- 

 bility of interference of the sound-waves in the air, is confirmed 

 by Dr. W. Scripture (Wundt's Philosophische Studien), who 

 further gives experimental ground for rejecting the hypothesis 

 of transference of the sound through the bones of the head of 



