1 64 



NATURE 



{Dec. 30, 1875 



keepers, constructing hives which they keep in trees. 

 Some families possess as many as 300 or 400 hives. 



About Mossamedes the Welwitschia mirabilis is found 

 growing, and the country about the river San Nicolau, 

 14° S. lat., seems to be its northern limit. Mr. Monteiro 

 sent home specimens of the plant, flower, and cones, 

 which supplied Dr. Hooker with some of the materials 

 for his monograph on the plant. 



It is impossible in our limited space to give any ade- 

 quate idea of the abundant information contained in 

 these volumes ; we can only assure our readers that if 

 they wish for satisfactory information about the country, 

 the people, the fauna, the flora, the geology, the mine- 

 ralogy of Angola, they will find it here. While an excellent 

 idea of the country as a whole will be obtained, the 

 author gives minute details of a very large number of 

 animals and plants, of the geology of certain parts, and 

 as to the various minerals which may be obtained, and 

 especially concerning the various tribes, their charac- 

 teristics, customs, implements, and other matters. The 

 numerous illustrations add not a little to the value of the 

 work. 



WORKS ON THE BLOWPIPE 



An Introduction to the Use of the Mouth- Blowpipe. By 

 Dr. Theodore Scheerer and H. F. Blanford, F.G.S. 

 Third Edition. (London : Frederick Norgate, 1875.) 



Pyrology J or, Fire Chemistry. By Major W. A. Ross, 

 R.A. (London : E. and F. N. Spon, 1875.) 



THE first of these volumes is a third edition of a well- 

 known little work, the second edition of which was 

 published in 1864. We think that it still holds its place 

 as the best elementary book on the application of the 

 blowpipe to the determination of minerals, although but 

 few changes have been made in the text. 



Major Ross's work on "Pyrology" is an imposing volume 

 illustrated with coloured lithographs. The preface looks 

 more like an article in a well-known daily paper than the 

 opening of a scientific treatise, for in the space of a few 

 pages the names of Neri, Cassius, Pattinson, Herbert 

 Spencer, Bacon, Sir W. Hamilton, Hume, Kant, Mrs. 

 Marcet, Walpole, Bonaparte, Grimaldo, and Hook are 

 alluded to, often in a flippant and tiresome way. The 

 introduction is much in the same style, and we are told 

 that " precisely the same operations of the mind are 

 necessary to analyse a murder or a miracle as a mineral," 

 and that "the general, the detective or the logician 

 deduces probabilities from facts . . . and the physicist or 

 pyrologist has first to elicit facts, which he calls reactions, 

 from which probabilities are concluded." A passage 

 which occurs on page 10 deserves notice. In it the author 

 states that "the various spectra in the orange, green, 

 violet, and indigo, &c., are due to the vapour of substances 

 composed of combinations of hydrogen, oxygen and 

 carbon, and thus that such lines seen in the solar spec- 

 trum should scarcely without further evidence be, as they 

 now generally are, attributed to the vapour of burning 

 terrestrial metals in the solar photosphere, but that our 

 metals should rather be supposed to be composed of 

 these elements in different proportions." Spectroscopists 

 will hardly consider the evidence he adduces in support 



of this hypothesis to be satisfactory, for it rests on no 

 better foundation than the fact that when small frag- 

 ments of zinc, lead, silver, aluminium and other metals 

 are heated before the blowpipe flame in a bead of phos- 

 phoric acid each metal with the exception of tin, gold, 

 platinum, and mercury is decomposed into a brick- 

 red oxide, a brownish black gelatinous mass, and 

 bubbles of some gas which smells like phosphuretted 

 hydrogen. 



An interesting and careful history of the use of the 

 blowpipe is then given, at the conclusion of which the 

 author alludes to his own labours, and after a careful 

 examination of the work, we are convinced that we shall 

 best do him justice by stating the principal observa- 

 tions that he claims as his own. These are — a method of 

 detecting soda by means of the orange colour which is 

 imparted to the " pure pyrochrome of boric acid." 

 Potash, on the other hand, being detected by the blue 

 colour pro,duced by breathing on a bead of boric acid 

 which has been blown into a thin vesicle, and in which 

 the mineral has been fused. The separation and detec- 

 tion of " lime and the alkaline earths " by fusion in a bead 

 of boric acid, when the oxides congest into small balls 

 which float in the clear bead. The use of phosphoric acid 

 as a solvent for certain metals, such as platinum and gold, 

 and the adoption of sheet aluminium as a support, which, 

 among other advantages, facilitates the roasting of arse- 

 nides and sulphides. In addition to these there are 

 between thirty and forty other " novelties " which space 

 will not permit us to enumerate. 



The nomenclature employed in the work is rather be- 

 wildering ; for instance, a flame having a conical shape is 

 termed "a pyrocone ;" a non-luminous flame tinged wilh 

 colour " a pyrochrome ; " and the crystallisation of sub- 

 stances from a state of fusion, is called " crystallignation." 

 It will be evident that such terms become almost irri- 

 tating when combined into words like " EUychnine 

 Pyrocone," which means a candle flame tinged with 

 colour. 



The tables for blowpipe analysis constitute a " Pyro- 

 qualitative Indicating Chart," which Major Ross has 

 divided into fourteen columns. Taking nickel, to which he 

 specially directs attention as showing the merits of the 

 table, we find that its reactions are described under three 

 heads. First, with phosphoric acid art amber brown bead 

 or, with little of the substance, an orange bsad is produced. 

 Second, with boric acid a bead containing green fragments 

 is obtained in the O.P. (oxyhydrogen pyrocone), and me- 

 tallic fragments in the H.P. (hydrocarbonous pyrocone), 

 and third, when the substance is heated on an aluminium 

 fusing tray in a "charcoal mortar" before the O.P. a 

 green hairy mass is produced. Anyone familiar with 

 blowpipe work will be able at once to compare mentally 

 these directions with Plattner's concise and well-known 

 tables which, by the by, are printed in the appendix. 

 In addition to the well known reagents he employs many 

 of unknown or uncertain composition, such as potassic 

 tungstic borate, mangani cobalt solution, and thus com- 

 plicates effects. We may give the following as an 

 example of the author's chemistry : — " Sulphides are in- 

 stantly detected upon it (aluminium foil) by fusing them 

 with a small fragment of soda, and saturating the hot 

 mass with a drop or two of water, when an inky black. 



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