February 6, 19 13] 



NATURE 



6ig 



of these phenomena. This postulates, for each 

 fibre (or cell), a semi-permeable investment 

 enclosing- a fluid of higher ionic concentration 

 than that outside it, and so represents each tissue 

 element plus its immediate environment as a con- 

 centration cell. 



From this point of view are first discussed 

 currents of injury and of activity — the former 

 attributed to outward diffusion of the cell (fibre) 

 contents (" pre-existence " in a new dress), the 

 latter to excitatory alteration in the permeability 

 of the "membrane." Electrotonic and thermal 

 currents, the dischargfe of electric organs, and the 

 law of electrical excitation are dealt with from the 

 same point of view. 



Nor is this all. " Electrobiology " is extended 

 beyond the above, more obviously electrical, 

 events. In addition, the activity of secreting and 

 of absorbing surfaces, karyomitosis, cell-life in 

 general, are presented as electrokinetic pheno- 

 mena. 



Prof. Bernstein's clearness and conciseness have 

 enabled him to condense a wealth of detail into 

 small compass with singular freedom from con- 

 fusion. His presentation is impressive and 

 interesting throughout, and it is to he hoped that 

 a work so peculiarly attractive to pre-graduate 

 as well as to post-graduate students of physiology 

 will find its way to early translation. W. L. S. 

 A Vertebrate Fauna of the Malay Peninsula from 



the Isthmus of Kra to Singapore, including the 



Adjacent Islands. Edited by H. C. Robinson. 



Reptilia and Batrachia. By George A. Boulenger. 



Pp. xiii + 2g4. (London: Taylor and Francis, 



1912.) Price 155. 

 This is the first instalment of a vertebrate fauna 

 of the Malay Peninsula of which the Federated 

 Malay States Government has authorised the 

 publication. The plan of the work is that of 

 Blanford's "Fauna of British India," to which it 

 mav be regarded as supplementary. References 

 to literature, especially in the case of species com- 

 mon to both fauna, have been made as short as 

 possible, though a fairly full synonymy has been 

 given for all forms which do not occur outside 

 Malayan limits. 



The descriptions throughout are based on the 

 collections in the British Museum, supplemented 

 in some few cases by specimens in the Selangor, 

 Perak, and Singapore Museums. 

 Who's Who in Science: International, 1913. 



Edited by H. H. Stephenson. Pp. xvi -1-572. 



(London : J. and A. Churchill). Price 8x. net. 

 Several improvements have been made in the 

 1913 issue of this useful work of reference. A 

 frontispiece giving portraits of certain eminent 

 men of science who died during 1912 has been 

 included, a new section on scientific societies and 

 their publications has been added, and biographies 

 of distinguished workers in psychology and geo- 

 graphy are given for the first time. Altogether 

 the editor has provided men of science with a 

 handy directory which should help to introduce 

 them to fellow-workers in various parts of the 

 world. 



xo. 2258, VOL. go] 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.^ 



Breath Figures. 



Lord Rayleigh, in Nature, December 19, 1912, 

 has again returned to the subject ot breath figures, 

 and his criticisms of my work on that subject 

 call for some remarks. Lord Rayleigh holds that 

 clean glass will give a uniform deposit of dew when 

 breathed on, and will look black, to use his expres- 

 sion, and show the colours of thin plates when pro- 

 perly lighted. I, on the other hand, think that the 

 character of the deposit is generally determined by 

 the impurities on the surface of the glass, because 

 the appearance of the deposit depends very much on 

 the treatment the surface may have previously re- 

 ceived. I came to this conclusion because there seems 

 to be no way of finding out what the deposit is like 

 on clean glass, as we have no means of knowing 

 whether the surface is clean or not. 



My reason for supposing that the black deposit 

 formed on the track over which a blowpipe flame had 

 previously passed was due to impurities deposited on 

 the cold surface by the hot gases, is that we know 

 that under these conditions fine dust and possibly some 

 gases must be deposited on the glass, and it is this 

 impurity which, I think, gives the black deposit. 

 Lord Rayleigh, on the other hand, supposes that this 

 black condensation is due to the cleansing effect of 

 the heat. If this be the case, then heat, apart from 

 the flame, ought to give the same result. In my 

 letter in Nature of June 15, 191 1, it is shown that it 

 does not. This experiment was repeated recently, 

 using higher temperatures. The result was no 

 change on testing with the breath ; the plate still 

 gave the white deposit. .\ part of the plate was then 

 passed over the flame, and, though not heated above 

 what could be comfortably handled, it gave the 

 black deposit. The black deposit in this case does 

 not seem to be due to heat, but to some effect of the 

 hot gases which will be referred to later. 



On reading Lord Rayleigh's paper I was greatly 

 Interested in his happy idea of breaking a piece of 

 glass and testing the broken surfaces before they got 

 contaminated by any impurity. The solution of the 

 question of the nature of the deposit on clean glass 

 seemed at hand, but on further inquiry it became 

 elusive, as we shall see. Following Lord Rayleigh's 

 example, very thick plate-glass was first experimented 

 with. When observing the condensation, in place of 

 breathing on the glass, the plate, with the newly 

 broken edge upwards, was pressed into pounded ice. 

 By causing the condensation to take place in this way 

 we get plenty of time for observing what is taking 

 place. The surface was watched, while the condensa- 

 tion was forming, by means of a strong magnifying 

 lens. My tests of the newly broken surfaces were 

 slightly different from Lord Rayleigh's. He got both 

 kinds of condensation — both black and white — while 

 in my tests scarcely any white was observed. Prac- 

 tically all the surfaces gave a black condensation ; 

 they acted as Lord Rayleigh thinks clean glass will 

 act. 



Other kinds of glass were also tested. The finest 

 results were obtained with the glass of a common 

 black bottle. The deposit in this glass gave very 

 fine colours, the black background showing them up 

 brilliantly. 



Having arrived at the conclusion that practically 



