5i8 



NATURE 



[March 29, 1888 



would be much enhanced by the addition of charts showing the 

 distribution in space and time, and by some discussion of the 

 results. It has been shown by M. Woeikof that the rainfall of 

 stations close together differs materially. For instance, at 

 Batavia the proportion of rainfall in the wettest and driest 

 months is 8 to I, while at Buitenzorg, only 25 miles distant, the 

 proportion is only 2 to i. The work contains a short account 

 of the position of every station. 



The Central Physical Observatory of St. Petersburg has 

 published a memoir on the rainfall of the Russian Empire 

 (506 pp. 4to) with an atlas. The data used in the calcula- 

 tions are brought down to the year 1882, and include observa- 

 tions taken at 450 places, embracing altogether 31 12 year?. 

 The tables contain individual monthly and yearly values, and 

 the means for the whole period, rainfall frequency, and maximum 

 falls in twenty-four hours. The influences of the form of gauge 

 and exposure on the amounts of rainfall, and of the method of 

 reckoning days of rain, are fully discussed. The amount taken 

 as representing a rainy day is '004 inch, while in England it is 

 'Oi inch. It is shown that the difference in the methods of 

 counting rainy days materially interferes with the calculations 

 based upon rainfall frequency. 



A SERIES of highly interesting experiments upon the vapour- 

 density of ferric chloride have lately been completed by Drs. 

 Griinewald and Victor Meyer. The chlorides of aluminium 

 and indium have already been shown by Nilson and Pettersson, 

 and by V. and C. Meyer respectively, to possess the molecular 

 formulae AICI3 and InCls ; it therefore became most important 

 to determine, if possible, whether the molecule of the cor- 

 responding chloride of iron possessed, as has been so generally 

 supposed, the constitution FcoCIg, or FeCIs- The pure ferric 

 chloride for use in the experiments was obtained by gently 

 heating fine iron wire in a stream of dry chlorine gas and re- 

 subliming the product, thus obtaining the salt in beautiful 

 hexagonal plates, exhibiting a fine green colour by reflected, 

 and a purple tint by transmitted light. The first determination 

 was carried out in a bath of vapour of boiling sulphur (448° C). 

 At this temperature, the lowest at which vapour-density estima- 

 tions are possible, the volatilization is very slow, but occm-s 

 without the slightest decomposition. And yet the vapour- 

 density obtained was considerably lower than that required by 

 the formula Fe^Clg, showing that at no temperature does ferric 

 chloride possess the molecular formula Fe.2Cl(3, but must of 

 necessity consist of molecules corresponding to the simpler 

 formula FeCig. On repeating the determinations at higher 

 temperatures in baths of phosphorus pentasulphide (518°) and 

 stannous chloride (6o5°), and in a platinum apparatus heated in 

 a Perrot furnace to temperatures of 750°, 1050°, and 1300°, the 

 numbers obtained gradually approached the vapour-density of 

 FeCls, the only unfortunate circumstance being that decomposi- 

 tion into ferrous chloride and chlorine occurred as the tempera- 

 ture was increased. However, on repeating the observations in 

 an atmosphere of chlorine, results almost identical with the 

 former ones were obtained ; hence there can be no doubt that 

 the true formula of ferric chloride is not FeoClg, but FeClj. It 

 follows from this as a matter of course that the former view as 

 to the tetrad nature of iron must be laid aside. It will be of 

 great interest, in view of this somewhat unexpected result, to 

 learn the results of the determinations of the vapour-density of 

 the lower chloride of iron, which, we understand from Prof. 

 Meyer, are being undertaken by Profs. Nilson and Pettersson. 



A THIRD edition of "Practical Amateur Photography," by 

 Mr. C. C. Vevers, has just been issued. This little manual is 

 intended to serve as a text book for the beginner and a handy 

 work of reference for the advanced photographer, and care has 

 been taken to make it eminently practical. 



An interesting book on "Tank Angling in India," by Mr. 

 H. SulHvan Thomas, has been published at Madras and in 

 London (Hamilton, Adams, and Co.). Anglers in India will 

 find in the little work — in which there are some fairly good 

 illustrations — an immense amount of information about paste- 

 baiting, live-bait picketing, live-bait with a float, worm and 

 prawn fishing, localities suitable for tank- fishing, stocking 

 ponds, the mainspring of fish-life, and names, description, and 

 habitat of fish. 



In No. 124 of the Proceedings of the Royal Society of 

 Edinburgh (session 1886-87) many valuable papers are printed. 

 Among the contents we may note : the sense of smell, being 

 Part III. of Prof. Haycraft's treatise on " The Objective Cause of 

 Sensation " ; on transition resistance at the surface of platinum 

 electrodes, and the action of condensed ga-^eous films, by 

 Mr. W. Peddie ; researches on the problematical organs of the 

 Invertebrata, by Dr. A. B. Griffiths ; the salinity and 

 temperature of the Moray Firth, and the Firths of Inverness, 

 Cromarty, and Dornoch, by Dr. H. R. Mill ; on the minute 

 oscillations of a uniform flexible chain hung by one end, and on 

 the functions arising in the course of the inquiry, by Dr. E. Sang } 

 notes on the biological tests employed in determining the 

 purity of water, by Dr. A. W. .Hare ; glories, halos, and 

 coronce seen from Ben Nevis Observatory, extracts from log- 

 book, by Mr. R. T. Omond ; on glories, by Prof. Tait ; 

 rectilineal motion of viscous fluid between two parallel planes, 

 by Sir W. Thomson ; and the thermal windrose at the Ben 

 Nevis Observatory, by Mr. A. Rankine. 



At a recent meeting of the Wellington (New Zealand) Philo- 

 sophical Society a paper was read by Mr. E. Tregear on " The 

 Origin of Fire " according to Polynesian folk-lore. Mr. Tregear 

 read from Sir George Grey's work the Maori legend of the pro- 

 curing of fire from the old fire-goddess Mahuika by the hero 

 Maui who had the power of becoming a bird at will, and com- 

 pared this with the Samoa version in which the fire-deity is a 

 male person, from whom Maui procures fire, having vanquished 

 him in a personal encounter. In the legend of another of the 

 islands the place of Mahuika as fire-deity is taken by the great 

 Polynesian god Tangaroa. From the fact that in these legends 

 the path by which fire was reached was always downwards into 

 the centre of the earth, Mr. Tregear suggests that it was 

 probable that the ancestors of the Polynesians had experience of 

 natural fire drawn from volcanic sources, but to Maui is due the 

 discovery in Polynesia of fire by friction. With regard to Maui 

 himself there is great difficulty in the parent-names. The 

 assumption by him at will of the form of the dove or of the hawk 

 is consistent with the belief in the ancient world of the various 

 shapes assumed by deities when desirous of accomplishing their 

 purposes. The "seed of fire," an expression used in tra- 

 ditions for the inflammable nature of certain kinds of timber, 

 was a common idiom in ancient Continental nations. Fire- 

 worship continued to have its devotees in Europe until com- 

 paratively recent times; and the sacred fire was always "new 

 fire " which had not previously been used for any purpose, 

 being kindled by friction. A legend is preserved in Eastern 

 Polynesia of the descent of the Maori people from a race whose 

 name is the same as that of the fire-kindling instrument used in 

 India," and it is remarkable that the deity who forges the 

 thunderbolts in India is probably identical in name with the 

 thunder-god of the Maoris. 



Dr. George M. Dawson has contributed to the Transactions 

 of the Royal Society of Canada (vol. v. section 2, 1887) a 

 valuable series of notes and observations on the Kwakiool 

 people of Vancouver Island. Referring to the question as to 

 the best means of doing good service to the Kwakiool, Dr. 

 Dawson says it is primarily essential to establish among them 



