458 



NA TURE 



[Septemher 6. I90D 



In the Atti dei Lincei, ix, 2, Dr. A. Campetti describes ex- 

 periments made with common salt and copper sulphate tending 

 to prove that there exists a difference of potential between a 

 solid salt and its unsaturated solution, this difference of potential 

 being of the same order of magnitude and sign as the difference 

 of potential between a more concentrated and a less concentrated 

 solution of the same salt. 



The question as to whether evaporation from the surface of 

 an electrified liquid produces a loss of electricity is one of con- 

 siderable interest in connection with theories of atmospheric 

 electricity. An investigation of this point is given by Signori 

 A. Pochettino and A Sella in the Atti dei Lincei, ix. i. The 

 method employed was to examine the rate at which an electrified 

 plate lost its charge under the varying conditions when its 

 surface was dry or was covered with a layer of water, and 

 when it was exposed to a current of dry air or air saturated with 

 watery vapour. The results tabulated show that the loss is more 

 rapid in dry air than in saturated air, that with saturated air the 

 presence or absence of the layer of water makes no practical 

 difference, but that with dry air the discharge is actually slightly 

 less rapid when the plate is wet than when it is dry. It is 

 inferred that evaporation does not produce loss of charge, that 

 the difference between dry air and saturated air is due to the 

 fact that the dry air was ionised, while all trace of ionisation had 

 been removed from the saturated air, and that the greater insula- 

 tion obtained with dry airby wetting the plate was due to the ionisa- 

 tion being partially removed by the evaporation from the plate. 

 In a paper published in the Proceedings of the Cambridge 

 Philosophical Society, Mr. Barrett- Hamilton suggests that the 

 (pathological) changes of colour and form which occur in certain 

 Salmonoids during the breeding season may afford a clue to the 

 origin of secondary sexual characters in animals in general. 

 " Once," writes the author, " the existence of such a primitive 

 state of things characterised by growth or discoloration of the 

 whole or part of the body is admitted, we have therein the 

 starting-point whence natural selection by alteration, suppres- 

 sion or accentuation of the details might easily produce many or 

 all the nuptial changes of animals as we now see them, evolving 

 in each a structure suitable to its own particular need, whether 

 in eye, as in the Eel, in snout, as in the Salmon, or in hind-limb, 

 as in Lepidosiren. 



Indian Musemn Notes (vol. v. No. i) contains an interesting 

 paper, by Mr. E. E. Green, on Indian Scale-insects (Coccidae), 

 showing the great increase which has recently taken place in 

 our knowledge of their various groups. So late as i886 only 

 seven Indian representatives of the family were recorded, the 

 well-known Wax-insect {Ceroplastes ceriferus) being one. Now 

 thirty-seven species, distributed among fourteen genera, are 

 known from Continental India, although this represents only a 

 very small proportion of the real number. Not only are these 

 insects interesting from their structure and their beauty of form 

 and colour, but some are of commercial importance. The 

 remainder of the number treats of various insect pests, notably 

 those infesting tea and coffee plants, and those destructive to 

 cereals and crops. 



The distribution of the Ruff in Ireland forms the subject of 

 an interesting paper, by Mr. C. L. Patten, in the Irish Naturalist 

 for August. 



The July number of the Agricultural Gazette of New South 

 Wales maintains the usual high and useful character of this 

 journal, an article on the important part played by bacteria in 

 soil being of especial interest to the scientific agriculturist. 



From the Indian Museum we have received " Illustrations 

 of the Shallow- Water Ophiuroidea collected by the Investigator,^'' 

 by Dr. R. Koehler, published by the trustees. The specimens 

 described are figured in eight plates. 

 NO. l6lO, VOL. 62] 



To the last issue of the Journal of the Asiatic Society of 

 Bengal for 1899, Mr. F. Finn contributes a paper on Indian 

 Weaver Finches (Ploceidae), in the course of which he shows 

 how a supposed new species has been named on a specimen of 

 a well-known bird in its summer plumage. 



Malacologists will find much to interest them in the sheets 

 of the Proceedings of the Philadelphia Academy last to hand, 

 Mr. H. A. Pilsbry communicating four papers .'dealing respec- 

 tively with the land snails of Japan, South America, Australia 

 and Polynesia, and India. 



Science Gossip for September contains an interesting article, 

 by Mr. R. J. Hughes, on the colouring of shells, in which he 

 demonstrates that the most common pigment among those of 

 northern Europe is the sesquioxide of iron. Another paper in 

 the same number forms the continuation of " Geological Notes 

 in the Orange River Colony," by Major Skinner, R.A.M.G. 



In the July number of the American Naturalist, Prof. H. L. 

 Osborn describes a remarkable Axolotl from Dakota, which 

 appears different from any named form, and niay indicate a new 

 type. In the course of his pxper the author raises the question 

 whether we yet know the adult of the true Mexican Axolotl, 

 the specimens that have developed into Salamanders being from 

 the United States and perhaps specifically distinct. 



We have received three fascicules of the "Results of the 

 Branner-Agassiz Expedition to Brazil," in course of publication 

 in the Proceedings of the Washington Academy. Two of these, 

 written by ladies, are devoted to Crustacea, while the third, by 

 Mr. C. H. Gilbert, deals with the fishes. When ladies appear as 

 authors of papers, it is much to be desired that they should prefix 

 "Mrs." or "Miss" to their names, as it is otherwise often 

 difficult to ascertain their proper titles. 



Mention in these columns has already been made of Mr. 

 G. S. Miller's work on Old World mammals, and we have now 

 received a paper, communicated by that naturalist to the 

 Proceedings of the Washington Academy of Sciences (vol. ii. 

 pp. 203-246), in which he describes a very large number of new 

 species, mainly Rodents, collected by Dr. W. L. Abbott on 

 islands in the North China Sea. Many of these are rats and 

 mice. 



The publication of Prof. E. Morselli's free course of lectures 

 on man from an evolutionary point of view is still proceeding, 

 and the fascicules when bound together will form an interesting 

 volume on physical anthropology, or, as the author terms it, 

 Antropologia gdn^rak. The last number to hand (No. 45) 

 concludes the section on the brain, and commences an account 

 of the progenitors of man. 



There is always something of interest in our well illustrated 

 contemporary. The Reliquary and Illustrated Archaeologist. The 

 July number contains some architectural notes from Monmouth- 

 shire, by Mr. J. Russell Larkby, illustrated by numerous 

 sketches, and a short paper, by Mr. R. E. Head, on lace bobbins ; 

 these are often decorated in various ways, and different parts of 

 the country furnish local types. 



Those who are interested in criminal anthropology will find 

 in a recent number of the Bulletin de la Society d Anthropologie 

 de Paris (Tome x. 4«= serie, p. 453) a psycho-physiological, 

 medico-legal, and anatomical study of an atrocious criminal 

 named Vacher, by MM. J.-V. Laborde, Manouvrier, Papillaut 

 and Gelle. It is strange that studies of this kind are never made 

 in this country. It is quite time that physical anthropology and 

 psychology were more directly recognised by persons interested 

 in criminology. 



Sir Archibald Geikie's " Outlines of Field Geology ' 

 (Macmillan) has been the counsellor and friend of many young 

 geologists and intelligent observers of the earth's features. A 



