4o8 



NA TURE 



[August 22, 1901 



784) ; clinical thermometers, 20,476 (increase 4456) ; total 

 number of instruments tested, 27,569 (increase 5518). The 

 principal addition to the staff during the year has been the 

 appointment of Dr. J. A. Harker as an assistant in the 

 Laboratory. Among the different appendices may be men- 

 tioned one showing the mean values of the magnetic elements 

 at observatoiies the publications of which are received. 



The first number has reached us of the " University of 

 Missouri Studies," a publication which it is proposed to issue as 

 irregular intervals as often as work of the required .standard it 

 offered by members of that University. The present number 

 consists of " Contributions to a Psychological Theory of Music," 

 by Dr. Max. Meyer, professor of experimental psychology. 



Prof. Angelo Andres, writing in the 'LonAizxAy Rendiconii, 

 discusses the choice of a base line in the so-called "rational" 

 measurement of animals according to which the various dimen- 

 sions are expressed in terms of one measurement, generally 

 representing the length of the animal. As a result of the con- 

 siderations brought forward by the author, the distances which 

 best satisfy the requirements in the selection of the base fall, in 

 the case of vertebrate animals, into six groups, according to the 

 particular class of animals considered. 



A STUDY of thenummuiites of southern Italy has been made by 

 Dr. Giuseppina Gentile, chiefly from observations of specimens 

 in the geological museum of the University of Naples. The 

 examples which the authoress describes, belonging to twelve 

 species and five varieties, come from the Middle and Upper Eocene 

 formations, the former being represented by a prevalence of the 

 forms N. laevigata, N. liitasaiia and N. feifoiata and the latter 

 strata being characterised similarly by a prevalence of iV. Tchi- 

 hatchcffi and N. Giietlardii. The paper is to appear in the Atti 

 of the Naples Academy. 



With the object of conducting researches in limnology in Italy 

 similar to those instituted in Switzerland by Forel, the Reale 

 Istitulo Lombardo appointed in 1896 a committee to investigate 

 the variations of temperature in the lake of Como, and a pre- 

 liminary report appears in the Kendtconti of the Academy, 

 xxxiv. II. The western limb of the lake is particularly suitable 

 for such observations, on account both of the regularity of its 

 basin and, more especially, on account of the absence of any 

 fluvial current of importance. The vertical distribution of tem- 

 perature is in conformity with the measurements obtained by 

 Burguieres and Forel. In connection with the annual variations, 

 the most remarkable feature (observed in two consecutive years) 

 was the irregular undulation of the curves at depths of twenty 

 and thirty metres, and in particular the appreciable cooling which 

 at these depths occurs in the hottest months. Observations 

 have also been made on the variations of long period, and 

 on the horizontal distribution of temperature across various 

 sections of the lake. 



The foitrnal of the Royal Microscopical Society for August 

 contains the full report of the paper to which we have already 

 alluded, by Mr. J. W. Gordon, on the Abbe diffraction theory, 

 very fully illustrated by a large number of diagrams. The 

 main point of Mr. Gordon's contention is that the diffraction 

 effects seen in the use of Zeiss's Diffractions Platte are produced 

 by the diaphragm itself. He maintains that the diffraction 

 theory has virtually been abandoned by Prof. Abbe himself. In 

 the discussion which followed, in which Prof. S. P. Thompson 

 and Mr. Julius Rheinberg took part, and which is also reported 

 in full, the prevalent view appeared to be that while Mr. 

 Gordon had successfully exposed the incorrectness of some of 

 the statements of Naegeli and Schwendener and of other expo- 

 nents of the theory, he had not succeeded in showing that these 

 errors were the necessary consequences of the theory. 

 NO. 1660, VOL. 64] 



M. Blondel concludes his paper on oscillographs and their 

 use in the current number of the Revite gi'nirak des Sciences 

 with an account of his work on the alternate current arc. The 

 paper contains a number of very interesting oscillograph curves 

 — the first to be published of those taken by Mr. Blondel's 

 double oscillograph — showing the variation of current and poten- 

 tial difference with an alternate current arc between carbons or 

 between carbon and metal. The general characteristics of these 

 curves are now fairly well known, either through the previous 

 papers by M. Blondel or through the exhaustive series of wave- 

 forms in Mr. Duddell's paper in the lournal of the Institution 

 of Electrical Engineers (vol. xxviii. p. i). Greater interest 

 attaches, therefore, to the curves showing the effect of an 

 alternating current superimposed on a direct current arc. The 

 form of these curves throws important light on the much- 

 discussed "negative resistance" of the arc. The curves pub- 

 lished by M. Blondel lead him to the conclusion that the value 

 of dVjdh. is very small, positive for cored and negative for solid 

 carbons. This ratio, the negative value of which, found \ty 

 Messrs. Frith and Rodgers, gave rise to the controversy alluded • 

 to above, is defined by M. Blondel as "the coefficient of 

 stability," which seems to us a very convenient term. 



A Report by Prof. T. E. Thorpe, C.B., F.R.S., on the 

 work of the Government Laboratory upon the subject of the use 

 of lead compounds in pottery, has been published as a 

 Parliamentary paper. It may be remembered that a detailed 

 report upon the use of lead compounds in the production of 

 pottery glazes and colours was prepared by Profs. Thorpe and 

 Oliver in 1899, and the conclusions were described in these 

 columns (vol. Ix. p. 18). Since the publication of that re- 

 port a large number of further experiments have been made 

 upon lead fritts and upon glazes containing their lead in the 

 form of lead fritt, and a second paper «as issued a short time 

 ago. The present paper embodies chemical evidence which 

 Prof. Thorpe has to offer in connection with the special Rules 

 drawn up for potteries as to the use of fritted lead and 

 its degree of insolubility. Fritted lead is a silicate or boro- 

 silicate of lead formed when "raw" lead, that is, red lead, 

 white lead or litharge is fused or fluxed with a part or the 

 whole of the silica, or of the silica and the other materials used 

 for the glaze. Potters agree that fritted lead can be substituted 

 for raw lead in every section of pottery manufacture, and it 

 was thought by the Department Committee (1893) on lead 

 poisoning that this would mitigate the evil, then very prevalent. 

 But there are different kinds of fritted lead depending upon the 

 proportions of the materials taken. Some lead fritts appear 

 to be little less soluble in dilute acids than raw lead, and 

 therefore have just as injurious an effect when they find their 

 way into the system of the potter and are dis.solved by the 

 gastric juice. Other fritts are nearly insoluble and therefore 

 innocuous. It is to ensure the use of such insoluble, or slightly 

 soluble, fritts that the efforts of the Home Office are now 

 directed. Practical difficulties have, however, arisen as to the 

 standard and tests of solubility, and Prof. Thorpe's report deals 

 chiefly with the objections which have been raised to the proposed 

 Rule on scientific grounds. 



Dr. R. W. Shufeldt, in the American Naturalist, dis- 

 cusses the osteology and systematic position of the auks and 

 puffins. After reviewing the various arrangements proposed by 

 other writers, the author considers that these birds should form 

 a suborder ( = order of most ornithologists), the Alcre, which 

 is connected, on the one hand, with the plover group through 

 the gulls and their allies, and on the other, through the petrels, 

 with the penguins, loons, grebes and their extinct toothed ally, 

 Hesperornis. In reality, this arrangement is not very different 

 from the one proposed years ago by Dr. Sclater, who placed 



