65 



NATURE 



[November i6, 189; 



The Calendar of the University College of Xottingham for 

 the thirteenth session, 1893-94, has just been issued. 



A " Bibliography of the Chinookan Languages " (including 

 the Chinook jargon) has been prepared for the Bureau of 

 Ethnology, Washington, by Mr. J- C. Pilling. 



Messrs. Perken, Son, and Rayment have published the 

 eighteenth edition of a little book on "Intensity Coils," and 

 the second edition of "The Magic Lantern: its Construction 

 and Use." Both books are suited to the wants of the scientific 

 amateur, 



Mr. Albert F. Calvert presents, in his "Mineral Re- 

 sources of Western Australia" (George Philip and Son), an 

 array of facts of particular interest to the capitalist and emi- 

 grant. Beneath the surface of that country lie belts and reefs 

 of gold-bearing rocks sufficient to satisfy the most avaricious, 

 and Mr. Calvert is desirous that the profuseness of these and 

 like mineral deposits should convince people that the country 

 offers " mighty possibilities" to enterprise. 



Dr. 1\L C. Cooke's " Romance of Low Life among Plants," 

 published by the Society for Promoting Christian Knowledge, 

 is an interesting and very readable book on cryptogamic vege- 

 tation. Though written in language " understanded of the 

 people," and full of romantic beliefs connected with plants in 

 a bygone age, scientific accuracy is not sacrificed, and scientific 

 words are not strictly tabooed, as they usually are in the diffuse 

 books designed for the popular palate. A larger number of 

 illustrations would render the book still more interesting and 

 valuable. 



Dr. a. R. C. Selwyn, C.M.G., F.R.S., the Director of the 

 Geological Survey of Canada, has had a catalogue prepared of 

 the fine stratigraphical collection of Canadian rocks exhibited 

 by the Survey Department at the Columbian Exposition. The 

 collection comprised 1500 specimens, illustrating all the forma- 

 tions known to occur in the Dominion of Canada, from the 

 Laurentian to the Pleistocene. Mr. W, F. Ferrier gives a few 

 explanatory notes with regard to the rocks represented in the 

 collection. 



If the number of books published on a particular subject can 

 be regarded as an indication of the interest taken in that subject, 

 we are led to the gratifying conclusion that physical laboratories 

 are rapidly increasing. Books dealing with practical physics 

 are constantly being published, and the last received by us — 

 " Practical Work in Heat," by Mr. W. G. Woollcombe (Clar- 

 endon Press) — shares the generally excellent character of works 

 of its kind. It is now believed by all men of science that 

 physics cannot be properly taught by lectures alone, any more 

 than chemistry, and the belief is slowly but surely causing our 

 schools and colleges to give facilities for such necessary prac- 

 tical work. ]Mr. Woollcombe's book includes sections on ther- 

 mometry, expansion, calorimetry, evaporation, and radiation. 

 Excellent experiments are described in each section, and their 

 performance does not necessitate the use of expensive apparatus. 

 In fact, the book contains a practical course in heat that we 

 should like to see introduced into every school which includes 

 physical science in its curriculum. 



Compounds of carbon monoxide with potassium and sodium 

 respectively have been obtained by M. Joannis, by the action 

 of gaseous carbon monoxide upon solutions in excess of liquefied 

 ammonia of the peculiar compounds which potassium and 

 sodium form with ammonia. M. Joannis has for several years been 

 investigating the nature and reactions of these latter compounds, 

 potassammonium and sodammonium, and the results of his 

 researches have been referred to in previous notes (see Nature, 

 vol. xliii. p. 399, and vol. xlv. p. 158). The reactions which 

 NO. 1255. VOL. 49] 



occur between these substances and carbon monoxide are of a 

 most interesting character, throwing light as they do upon the 

 nature of the dangerously explosive compound of potassium and 

 carbon monoxide which formerly produced such deplorable 

 accidents during the commercial pioduction of metallic potas- 

 sium by the method of Brunner. A considerable number of 

 investigations have been carried out with the object of obtaining 

 a complete knowledge of this explosive substance, but the re- 

 sults arrived at can scarcely be termed concordant. Most of the \ 

 investigators agree in assigning to it the simple formula KCO, 

 but the descriptions of its properties are very diverse. Liebig 

 and likewise Lerch describe it as a black powder, while Brodie 

 endows it with a red colour. The latter chemist found it to 

 react in a most violent manner with water, while Liebig's sub- 

 stance was much more gentle in its demeanour towards that 

 solvent, and actually permitted of the application of a moderate 

 heat with no more serious result than quiet inflammation. More 

 recently Nietzki and Beuckiser have described it as not only ex- 

 plosive but as detonating, when exposed to the moist atmosphere, 

 under the influence of the least concussion in its neighbourhood. 

 The potassium compound now described bears most resemblance 

 to the unstable substance of Brodie and of Nietzki and 

 Beuckiser, although differing in several particulars. The 

 analogous sodium compound does not appear to have been pre- 

 viously obtained. 



When dry carbon monoxide is allowed to bubble through a 

 solution in liquefied ammonia of potassammonium, the blue sub- 

 stance of the probable composition (KNH3) n produced by dis- 

 solving metallic potassium in liquefied ammonia, the containing 

 vessel being cooled to - 50°, the deep blue colour gradually 

 diminishes in intensity, and is eventually supplanted by a pale 

 rose tint, the attainment of which signifies the completion of the 

 interaction. Upon removal from the cooling mixture the lique- 

 fied ammonia gradually vaporises, depositing as it does so a rose- 

 coloured powder which upon analysis proves to be pure 

 potassium carbonyl KCO. When left undisturbed in a sealed 

 tube for some time this pink powder darkens in colour, then 

 answering very closely to the description of Brodie's substance. 

 It cannot be heated to the temperature of boiling water, explo- 

 sion ensuing considerably below that temperature. Detonation 

 likewise occurs if the merest trace of air is admitted, and 

 instantly when touched with a drop of water. Air and water 

 both appear to act by causing such an elevation of temperature 

 by their reaction with a small portion as to bring about sudden 

 decomposition of the whole. It is, however, possible to study 

 the reaction with water by admitting a drop of that liquid into 

 an exhausted tube containing potassium carbonyl in such a 

 manner as not to come into direct contact with the substance ; 

 the aqueous vapour then slowly reacts with the apparent pro- 

 duction of deliquescence and the eventual formation of a yellow 

 viscous liquid. The nature of this liquid is reserved for a future 

 communication. 



Sodium does not resemble potassium in directly uniting with 

 carbon monoxide. Sodammonium (NaNHj);/, is, however, 

 readily decomposed by carbon monoxide with formation of 

 sodium carbonyl, NaCO, a substance which may be isolated in 

 a manner similar to that employed for the isolation of the 

 potassium compound. It is a pale lilac-coloured substance 

 which is powerfully explosive like its potassium analogue. 

 Detonation ensues under the influence of small quantities of 

 either air or water. Under the influence of heat its colour 

 darkens, no gas is evolved, but about 90° sudden explosion 

 occurs, and with such force that no glass has yet been found to 

 withstand it. It also explodes like the potassium compound 

 under the influence of percussion, although not quite so readily 

 as the latter substance. Tiie nature of the changes occurring in 



