i6 



A' A TURE 



[November 2, 189; 



case of paraffin his results agree with those obtained by Trouton ; 

 when, however, a metal is used as the reflector he finds that the 

 plane of polarisation is parallel to the electric force. The author 

 has measured the refractive index, for oscillations having a 

 wave length of 7*5 cm. of the paraffin used in his experiments. 

 He employed for this purpose an equilateral prism, each face 

 being 20 cm. high and 37 cm. broad, and found i '\ for the refrac- 

 tive index. The paraffin employed was not of the highest 

 quality, although it was quite white and homogeneous, and had 

 a melting point of 5o''5 C. 



Dr. Oettel has continued his researches on the phenomena 

 of the electrolytic deposition of metals (see Nature, July 6, 

 1893). In the present paper, which is published in the Chemiker 

 Z itung, he gives the results he has obtained in his investigation 

 of the condition of an auxiliary electrode placed between the 

 two principal electrodes in a copper voltameter. For an 

 auxiliary electrode 86 by 131 mm. in size, being a little smaller 

 than the principal electrodes, he finds that copper is deposited 

 on the side next the anode, and dissolved at the side next the 

 cathode ; the quantity dissolved being larger than the quantity 

 deposited in nearly the same proportion as at the principal 

 electrodes. This difference is caused by the electrodes not 

 being composed of pure copper. The deposit on the auxiliary 

 electrode attains as much as 87 p;r cant, of the deposit on the 

 cathode; but depends on the following conditions: — (i) The 

 relative dimensions of the auxiliary electrode and of the chief 

 electrodes. (2) The absolute size of the electrodes ; for, since 

 the copper tends to be deposited chiefly at the edges, the 

 proportion increases when the plates are' small. 



In order to ascertain if lifle bullets are capable of carrying in- 

 fection, Messner [Minuhenei- med, Wochensdirijt, 1892, No. 23) 

 has been making careful experiments with bullets purposely in- 

 fected with particular micro-organisms. Bullets thustreated were 

 discharged into tin boxes at a distance of from 225 to 250 metres. 

 These boxes were filled with sterile gelatine peptone, and the 

 channel in the latter made by the passage of the bullet was care- 

 fully watched and examined. It was found that in all cases 

 the infected bullets had produced growths of those organisms in 

 the gelatine with which they had originally been brought in 

 contact. In some experiments the boxes, whilst filled with 

 sterile gelatine, were covered over with flannel previously 

 infected with particular bacteria, so that before reaching the 

 gelatine the bullet would first have to pass through the former. 

 Ordinaiy uninfected bullets were used, but in every instance 

 bacterial growths made their appearance in the subjacent gela- 

 tine corresponding to the particular organisms present on the 

 flannel. On the other hand, ordinary bullets, when discharged 

 direct into the gelatine, occasioned only the appearance of 

 moulds and other bacteria usually found in the air. Thus the 

 heat communicated to the bullet during its discharge is not 

 sufficient to destroy any bacteria which may be present upon it ; 

 the temperature produced is also wholly inadequate to sterilise 

 any portions of clothing with which the bullet may come in 

 contact, the latter, on the contrary, carrying with it into the 

 wound those bacteria which may be present on the former. 



With regard to the physiological action of oxygen in as- 

 phyxia, more especially in coal mines, a committee of the 

 British Association has arrived at the following conclusions : — 

 ^i) In the case of rabbits asphyxiated slowly or rapidly, oxygen 

 is of no greater service than air, whether the recovery be 

 brought about in an atmosphere contaminated by carbonic 

 acid or compleVely free of carbonic acid, and whether artificial 

 respiration be resorted to in addition or not. (2) Pure oxygen, 

 when inhaled by a healthy man for five minutes, produces no 

 appreciable effect on the respiratory rate and volume, nor on the 

 pulse rate or volume. (3) Oxygen, whether pure or somewhat 

 NO. 1253, VOL. 49] 



diluted, produced no effect on one particular patient, who suf- 

 fered from cardiac dyspnoea of moderately severe type, in the 

 direction of ameliorating the dyspnoea, and, compared with air 

 inhaled under the same conditions, produced no appreciable 

 effect, either on the respiratory rate and volume or on the pulse 

 rate and volume. (4) An animal may be placed in a chamber, 

 the general cavity of which contains about 50 per cent, of car-" 

 bonic acid, and retained there for a long time without super- 

 vention of muscular collapse, provided a gentle stream of a 

 respirable air gas or oxygen, indifferently, be allowed to play 

 upon the nostrils and agitate the surrounding atmosphere. 



The Quarterly Journal of the Geological Society (No. 196) has 

 been issued. 



Messrs. Dulau and Co. have issued a catalogue of works 

 on Lepidoptera, Neuroptera, and Orlhoptera. 



Messrs. Whittaker and Co. have published a pamphlet, 

 by Capt. M. P. Nadieine, on a new system of sanitary drainage 

 and treatment of sewage matter. 



The Matabele War has induced Mr. E. P. Mathers to issue 

 a "Map of Mashonaland and Matabeleland." A few facts 

 about the Matabeles and their country give the map additional 

 interest. 



We have received a paper on " Rainmaking," read before 

 the Texas Academy of Science in December 1S92, in which Dr. 

 A. Macfarlane discusses professional rain-makers (not the 

 medicinemen of the Indians, but their civilised prototypes) and 

 disposes of their theories seriatim. 



Though Mr. A. T. Burgess's "First Stage Agriculture" 

 (Joseph Hughes and Co.) is adapted to the Elementary Syllabus 

 of the Department of Science and Art, it should be valuable to 

 all students of agriculture. The author is concise in his state- 

 ments, so he has been able to give a large amount of informa- 

 tion in a small book. A scarcity of illustrations is the book's 

 only fault. 



" The Birds of Michigan," by Mr. A. J. Cook, are described 

 in Bulletin No. 94 of the Michigan State Agricultural College. 

 The bulletin is illustrated and contains a bibliography. In the 

 text are recorded the food habits of the birds ; so that the 

 economic importance of the various species can be judged. A 

 section is devoted to a statemeni: of the laws that obtain in 

 Michigan for the protection of game. The list is a useful con- 

 tribution to the ornithology of an interesting region. 



A USEFUL book on the "Analysis of Milk and Milk 

 Products," by Prof. Henry Leffmann and Dr. William 

 Beam, has been published by Messrs. P. Blakiston, Son and 

 Co., Philadelphia. The book appeals particularly to Ameri- 

 can agriculturists, but it may be introduced with profit into 

 the dairy schools springing up in various parts of the country, 

 and professional chemists will be interested in some of the 

 analytical methods described. 



Mr. Hugh Gordon's "Elementary Course of Prac.ical 

 Science," part 1, belonging to the series of Science Primers pub- 

 lished by Messrs. Macmillan and Co., is worthy of introduction 

 into all elementary and continuation schools. The experiments 

 described are of a very simple nature, and refer to every-day 

 phenomena. The pupil who conscientiously works through 

 the little book will certainly have impressed upon him the im- 

 portance of exactness, and will thus be given the best foundation 

 of a scientific education. 



Another book on practical physics is "Lessons and 

 Exercises in Heat," by Mr. A. D. Hall (Rivington, Percivaland 

 Co.) The book contains a series of lessons and exercises, and is 



