July 23, 1896] 



NA TURE 



279 



Sheridan Delepine ; and there will be a discussion on the 

 relation of the morbid conditions dependent on (or associated 

 with) the presence of streptococci. Ur. David Little will pre- 

 side over Section G (Ophthalmology'), Dr. J. Finlayson over 

 Section H (Diseases of Children), and Dr. T. F. I'Anson over 

 Section I (Medical Ethics). A number of garden parties and 

 other social functions have been arranged, and these will help to 

 lighten the large amount of work which the various Sections 

 will have to do. 



It was shown by M. H. Moissan, about three years ago, that 

 when iron was saturated at 3000' C. with carbon, and then 

 cooled under a high pressure, a portion of the carbon separated 

 out in the form of diamond. It occurred to M. Rossel {Compt'.s 

 reiidiis, July 13), that the conditions under which very hard steels 

 are now made, should also result in the formation of diamonds ; 

 and an examination of a large number of samples of such steel 

 has shown that this is really the case. The diamonds are 

 obtained by dissolving the metal in acid, and then subjecting the 

 residue to the action of concentrated nitric acid, fused potassium 

 chlorate, hydrofluoric and sulphuric acids successively. The 

 crj'stals are very minute (about 15 jifi), the largest attaining 

 only 0'5 mm. in diameter, but they present all the chemical 

 and physical properties of true diamonds. 



The detection and estimation of small amounts of marsh gas 

 in air is a problem of considerable practical importance in the 

 ventilation of mines, and numerous instruments having this object 

 have been designed. In the May number of the Bulletin de la 

 SocitlJ d' Encouragement pour C Industrie Nationale, Mr. E. 

 Hardy describes a new apparatus for this purpose which presents 

 many novel features. The principle utilised is the variation of 

 the velocity of sound in a gas with its density. The air under 

 examination is forced through a small organ pipe, and the note 

 thus produced compared with that given out by a second pipe 

 fed under parallel conditions with pure air, the number of beats 

 per second produced giving a measure of the methane present, 

 the apparatus being so arranged that the moisture, carbonic acid, 

 and possible variations of temperature exert no influence on the 

 result. Three types of instrument are constructed, portable, 

 fixed, and self-recording. In the second type a telephone from 

 any convenient place is put in connection with two microphones 

 placed on the organ pipes, so that by simply counting the number 

 of beats, the manager can instantly recognise from his ofiice the 

 presence of fire-damp in the part of the mine from which the air 

 is being drawn, l per cent, of methane giving about three beats 

 per second. The only drawback to this ingenious apparatus is 

 that it is rather complicated in detail, and therefore costly, 

 especially in the self-recording type ; but the advantages of ex- 

 treme simplicity in actual use, combined with the convenience 

 attaching to the telephone, will doubtless outweigh this in 

 practice. 



In a paper on gall-making coccids, contributed by Mr. C. 

 Fuller to the Agricultural Gazette of New South Wales (vii. 4), 

 some details are given concerning the genus Brachyscelis, the 

 members of which live exclusively upon species of Eucalyptus, 

 causing the growth of woody galls, in the heart of which they 

 dwell. These coccids are popularly known in Australia as 

 " gall-makers," but the gall-growth differs from the " meal " of 

 the mealy-bug and the "scale" of the bark-louse — which are 

 other .\ustralian species of Coccid;e — in that it is brought into 

 existence at the actual and direct expense of the tissue of the 

 plants, whilst the meal and the scales are products secreted or 

 excreted from the bodies of the insects themselves. The larva- 

 of all Brachysceles are so similar in appearance as to afford no 

 sufiicieni characteristics for the determination of species. The 

 male galls lake the form of short cylindrical tubes, not e.xceeding 

 NO. 1395, VOL. 54J 



six lines in length, and generally growing upon the leaves. 

 The female galls exhibit a great variety of forms, which supply 

 the easiest means of distinguishing the different species, and 

 \yhich vary in length from half an inch to six or seven inches. 

 Some resemble cones, others nuts and fruits, whilst the latera 

 growths, due to B. duplex, are not unlike leaves. Occasionally 

 supported on stalks, they are more often sessile upon tlie branches, 

 twigs, or leaves from which they spring. These abnormal 

 members of an aberrant group like the Coccidx should repay 

 further study. 



Do varieties of peas run out ? This problem is dealt with in 

 Bulletin No. 131 of the Michigan Agricultural Experiment 

 Station, and the answer is that varieties at least lose their original 

 characteristics. Such '• running out," however, does not neces- 

 sarily imply deterioration, as sometimes it is merely a changing 

 of characters. Accurate descriptions accompanied by drawings 

 are kept of varieties of peas grown at the station. These serve 

 to show that varieties change from year to year — even the old 

 standard sorts, the characters of which are supposed to be firmly 

 fixed. The foliage and habit of the plants are found to be less 

 variable than the peas themselves, which are generally the object 

 of selection. The variety Stratagem was grown from seed ob- 

 tained from three diflerent dealers. In all, the characteristic 

 dark green foliage, stalky, angular veins, and exceedingly short 

 nodes of the variety named were apparent. But the pods, though 

 irregular and varying in each sample, yet, taken as a whole, were 

 distinctly diflerent. In two of the samples the pods were fairly 

 uniform, but in the third they were so irregular — probably re- 

 versions to one of the parents — that the peas were almost worth- 

 less. It is a matter of common observation that seed peas of 

 the same variety, especially the wrinkled sorts, differ in colour 

 as supplied by diff'erent seedsmen. In several cases peas grown 

 on the station grounds have changed the colour of their seed 

 within the last four years. 



A BRIEF statement of the facts as to the anti-cholera serum 

 experiments carried out by Prof. Kitasato, of Tokyo, is made 

 by Dr. A. Nakagawa in the current number of the British 

 Medical fournal. Preliminary experiments in the laboratory 

 for ascertaining the curative action of the serum were carried on 

 in this wise : A number of guinea-pigs were inoculated with 

 several times the fatal dose of the virus, so that the untreated 

 animals died within twenty hours after such inoculation. At 

 the expiration of each successive hour injections were made in 

 some of the animals, and it was shown that those treated not 

 later than seven hours after the inoculation of the virus were 

 cured, while those in which the injections were made after the 

 lapse of seven hours could not be saved by the serum. In other 

 words, if injected during the first third of the entire course of 

 the disease (thus experimentally produced) the serum can be 

 considered curative. Cases of cholera were afterwards treated 

 with anti-cholera serum at the Hiroo Hospital, Tokyo. Of 

 270 cases admitted, 138 died, which gives a rate of mortality of 

 51-1 per cent. Anti-cholera serum was employed in 193 cases 

 only, owing to the fact that the supply of serum was inadequate 

 to allow it to be used in all cases. The rate of mortality among 

 Japanese in nearly all the previous epidemics, as well as that of 

 the last epidemic, has always been about 70 per cent. Without 

 claiming to draw, from a number relatively so small, the final 

 conclusion that the serum treatment was attended with the 

 reduction of 20 per cent, in the mortality statistics, it is evident 

 at least that the result of the new therapy was not an unfavour- 

 able one. Moreover, Dr. Nakagawa thinks there is reason 

 to believe that, with a sufficient supply of very eflicient serum, 

 the rate of mortality can still be lowered. 



Students of Japanese culture will be interested in a paper 

 on " .Anatomy and .Esthetics among the Japanese," in Globus 



