lO 



NATURE 



May 



1895 



Charles Urummoiul. Trnisurer. anil Dr. Sclatcr. Secrclar)-. to 

 the Society for the ensuing year. 



The first of the two conversaziones held at the Royal Society 

 every year, takes pU-ice as we go to press. Annual receptions and 

 exhibits, conducted ujwn much the same lines, are gradually lx;ing 

 instituted by learned societies in various ]>arls of the world. The 

 Xew York Academy of Sciences recently held a similar exiiibition. 

 at which five hundred diflercnt objects of scientific interest wen 

 shown. From a report in the Sticulific AiturUaii, it api>ear> 

 that many of the exhibits were of a very striking character. .\ 

 numl)er of photi^a])hs of comets, of the Milky Way, and of 

 star s])eclra. were shown by Profs. Barnard and Keeler, of 

 the Lick and .\llegheny Obscr\alf)ries. (Jne of the most novel 

 exhibits in physics, was a series of Chlaclni figures, shown by 

 Vxni. Alfreil M. Mayer. The figures were formed in while 

 .*and upon vibrating metallic plates. I'rof. Mayer's process 

 consisted in fixing the sand upon a black background after the 

 figures ha<l been formed, by means of a fixative spray. Thesi- 

 plates demonstratcil the truth of Lord Rayleigh's theoretical 

 deductions, and tliffered radically from all figures which are 

 shown in text-bo<iks in the fact that none of the lines intersect. 

 The physical exhibit Wiis an extensive one, including a large 

 number of instruments for .-iiwctroscopic. as well as for sound and 

 light, measurements. The mineralogical exhibit included alxmi 

 one hundred objects. Biolog)- was represented by preparations 

 i>f nerve cells from the brain and spinal coril, by Prof. (lolgi's 

 methfid ; and there were also shown several series of similar 

 pictures iK-aring upon problems of inheritance, both in animals 

 and plants. Bacteriologj'. mechanics, physioU^-, experimental 

 psycholog)-, anatomy, gcolog)-. and jjaheontology all look |iarl 

 in the exhibition. In vertebrate |>ala.ontolog)-, the main exhibit 

 was that showing the evolution of the horse. The series 

 connecting the oldest known horse of the LoweK ■■".oiene period 

 with the mixlern horse was prr)bably the most complete which 

 has e»er tieen brought logelher. The little four-toed horse, 

 recently acquired by the .\merican Museum of Natural History 

 from the collection of I'rof. Cope, of Philadelphia, was exhil>ile<l. 

 .\Uhough fully matured, it is only 3 J hands high. The skull and 

 limlis, nevertheless, display the char.acteristics of the horse. The 

 teeth are shtirt and simple : the limbs are scarcely larger in 

 diameter than a good-sized pencil, ami there are four toes, all 

 resting upon the ground, in the fore-foot. .\ remarkable series 

 of feel was also exhibited, giving all the stages Ijetwecn this 

 four-toci horse and the mmlem one-toed animal. The reception 

 at which the exhibits were shown w.xs s<i successful that it has 

 lieen decided to hold a sintilnr one every year. 



IJK. Bkktram Wixiii.k contributes a |M|)er to the /oiinial of 

 .Anatomy and Physiology, " On the efl'ccts of ICIectricity and 

 Magnetism on development." The ol>ser\ations recorded were 

 made on developing silkworms, trout, anil chick embr)os. In 

 ihc case of the chick, the numlicr of abnormally ilevelo|x.-d 

 embryos was much greater in eggs inculmted aroun<l the jmles 

 of a strong nuignet than usual. With one exception all the mal- 

 tormations were associate<l with tleficienl development of the 

 v,i.scidar area. Dr. Windle has not conclusively shown that this 

 large projxjrtion of abnormal enibry-fw was .iclually due to the 

 " ' f" ' ^ ' niMgnel. yel his resiills on the whole agree with 

 ■ • ' ' r.ini. ^ilthough certain |>riints of difference were 



i-':'\ in ih..- clufeiiiii- embryos. The eggs of the silkworm 

 were found li. dcM-lnp ipiite normally in a strong magnetic 

 IilM. An electric current |nssing through a lank in which trout 

 ova had Ijeen placed, seemeil to produce an arrest of develop- 

 ment. Dr. Windle concludes from bis <iwn observations and 

 those of other authors, "that elcclricily proiluces an arresting 

 effect upon devclofmieni," while it is " very doublful whether a 

 iii.i^jiielic field ha« an) 'lefinile effeii ii|kim development or not.'' 

 NO. 1331, VOL. 52 I 



; -A RECENT number of Comptes tendiis contains an interestini; 

 i pa]>er by M. Branly. on the rate of loss of an electric chariji- 

 I due to the effect of light in the case of Ixidly-conducting Ixidics. 

 When the source of illumination is a body heated to a dull red, 

 it is the condition of the illuminating surface which plays the 

 chief part in the phenomenon. The nature of the charged bod\ 

 seems to have no effect. In the cise where the illumination i^ 

 rich in highly refrangible rays, however, the cise is quite 

 different, and the chief results obtained are as follows: — A 

 disc of wood or marble, polished ttr unpolished, shows a marked 

 loss of electricity when illuminated. If the disc is negativel) 

 electrified, the loss is more rapid than if it is [xisitively electrifieil : 

 but the difference is verj- nnich less marke<l than is the case w ith 

 metal discs, jxtrticularly if they are i^)Iished. Similar results 

 are obtained with cardlxiard, terra-cotta, and glass heated to 100°. 

 The loss of a positive charge is rapid, while that of a negative 

 one is slow in the case of varnished wood, or woo<l coaled with ;i 

 thin Layer of oil, jiaraftin or tallow. With a metal disc coated 

 with tallow, the loss when negatively ele-ctrified is slow, while 

 the loss when positively electrified is very rapid. If a disc of 

 [wlished wood, in which the loss of a neg-ative chaise is more 

 rapid than that of a positive one, though the diflerence is not 

 very marked, has the surface covered with a thin ccxiting i>f 

 phimliago, the loss with a negative charge becomes nuich more 

 rapid than with a jmsitive one. A metal plate covered with 

 grease only loses a negative charge verj- slowl)', the rate of loss 

 of a positive charge being rapid. If, however, a thin coating of 

 copiKT filings is spread over the tallow by means of a sieve, the 

 loss with a |X)sitive charge liecomes much more rapid than with 

 a negative one. If powdered aluminium is used in tlie jilace of 

 cop|x-r, the rates of loss in the case f)f ixisitive .and negative 

 charges iK'come nc-arly etjual. 



The Unite<l States Deiiartment of .\gricullure publishes, in 

 I Hiiltctiii No. 6 of the Dei>artment of X'egetable Pathology, a 

 tietailed |iaper, by Mr. D. CI. I'airchild, on the use of " Bordeaux 

 I Mixture," a pre|)aration of copix.'r -sulphate .and lime, as a fungi- 

 I cide ; and the motle of treatment of a number of diseases of 

 I fruit-trees, corn-crops, and garden plants caused by fungi. 



The ninth e<lltioii has just been Issued of ]jart I of the London 

 I Cala/ogw of Brilifli Plants, comjirising the Phanerogami;i, 



Kilices, li(|uisetace-.v, Selaginellace;e, Marsileace;e, and Characea. 

 I The changes introduced in this edition represent the results of 



the field-work, the critical stuily of Hritish plants, and the 

 ! researches on nomenclature, made during the last nine years. Ii 



is now edited by Mr. V. J. llanbury. 



Tlitc ])art of the Agricnllnral Gazette of New South Wales for 

 Januar)' i895ischlefly occupied by papers on prailical .agriculture 

 ami breeding. I'Vmr s|H.'cies of so-called ntahi>ganies of New 

 South Wales are descrilieil by Mr. J. II. Maiden, all species of 

 Enialyptns. The life-history of ihe I'liyllo.xera ;astatn.\, an<l 

 Ihe injuries inflicted liy it on the vine, are descril>ed at length ]<\ 

 Mr. J. A. l)es|Kissis. anil are illustrated by a coloure<l plate and 

 numer«)us wotMlcuts. 



With the title .lllgiimine liotanisihc iicitsihrift fiir System- 

 atik, Florhtik, iind Pflanungeografhic, a new monthly botanical 

 journal has been starteil at Carlsruhe, under the eilitorship of 

 Ilerr \. Kneucker. Its aim is especially to deal with the study 

 of difficult groups of plants, diagnoses of species, critical form-, 

 anil hybrids, geographical bnlany, and the results of the travels 

 of botanists. 



In the llnlUtin No. y of \.\\\: Minnesota Holaniia/ SIndieshan 

 Interesting article by Mr. .\. P. .\nderson, on the (irand Period 

 of CiroHlh in the I'ruit of Cnaiyhita frpo. Krom the time of 

 fertilisation to thai of ripening, the devch)puient may be divided 

 into three |»erlrnls -a i)eriiKl of active and condnuous increase 



