'76 



NA TURE 



[July i8, 1895 



whose edges are towards the red. One sjiectrum is just as 

 complete as the other, neither one being a development of the 

 other. The band si)ectruni corresponds to a trifle lower tem- 

 perature than the new line si)ectrum ; but it is difficult to see 

 how complexity of molecular .structure can account for the dif- 

 ference between the two spectra in the case of mercur)-, whose 

 \-apour is monatomic. This has, of course, a most important 

 bearing on the theory of band and line spectra, and seems to 

 decide definitely against some of the present ideas concerning 

 them." 



The current numlwr of M'itdemaiiii' s Annalen contains a 

 paper by Herr J. E. Myers on the influence of gases dissolved 

 in the electrolyte of a silver voltameter on the w eight of deposited 

 .silver. The author finds, as has previously been shown by 

 Schuster and Cro.ssley, that if the same current is sent through 

 two voltameters containing neutral solutions of silver nitrate of 

 the same strength and at the .same temperature, one voltameter 

 being in a vacuum and the other in air, then the weight of the 

 silver deposited in the v.acuum voltameter is, for a solution 

 containing from 20 to 40 \xx cent, of silver nitrate, about O'l 

 l>er cent, greater than that of the silver deposited in the other 

 voltameter. For a 5 per cent, solution, the diflerence is some- 

 what smaller. If the solution is saturated with carbon dioxide 

 the deposit is alx>ut 0"055 per cent, lighter than when the 

 solution is saturated with air. With nitrogen, however, the 

 <leposit is almut O'OS i>er cent, heavier than with air. The 

 electrical resistance of a 5 jier cent, solution saturated with air 

 is practically the same as that of the same solution in a vacuum. 

 With a current of more than 0'2S ampere, it is found that in 

 vacuum an evolution of gas takes |ilace at the anode. The 

 author has also examined the grey deposit which is formed on 

 the anode, and finds that it consists of pure silver oxide. 



Thk results of some observations on declination made by M. 

 Ch. I^grange, which, if unaffected by some unsusjiectcd error, 

 are most unexpected, are given in a recent number of the 

 Coiiiflts rcndtis (June 17, 1895). During the last three years the 

 author has been making observations of declination at the Ucclc 

 Observatory at Brussels, using for this purpose magnets having 

 very different magnetic moments. He finds that systematic 

 rliffercnces occur in the values obtained, but what is most 

 xslonishing is that diminution, within certain limits, of the 

 magnetic moment of the magnet causes an amplification of the 

 observed changes in declination. In one set of observations, 

 lasting for six months, one of the magnets consisted of the 

 almost astatic m^netic .system taken from a galvanometer. 

 By comparing the readings obtained with this system of magnets 

 wilh those obtained on the self-registering magnetometers, it 

 was found that the amplitude of the movements of the galva- 

 nometer needle was from fifteen to twenty-five times as great 

 a-s that of the magnetometer needle. Another set of observations 

 have iK'en made wilh a large steel magnet, only feebly 

 magnetised, however, .so that its magnetic moment was only 

 alKiul Vt of '''•'•' of 'he magnet of the magnetograph. This 

 magnet wa.s suspended by a fine platinum wire, and here again 

 ihc amplitude of movement of the feebly magnetised bar was 

 greater than that of the more strongly magncti.sed one. 



Wk have received BiilUlins Nos. 1 19-124 of the Michigan 



.Agricultural Kx|x;rimcnl Station, dealing with a variety of subjects 



<if horticultural interest. Wilh regard lo the troublesome 



diicaM; of tomato rot, which is often the cause of serious loss, it 



Sat spraying with Bordeaux mixture is cflicaciou.s. 



1 11. when the tomatoes had grown to the size of 



linLn) i.ui». ilie plants were given a thorough spraying, and 



Ihre"- »<-<-l,v Imr ili<- application was repeated. \ery little rot 



I lyed plants, whilst on those which were 



id many diseased fruits were to l>e seen. 



NO, 1342, VOL. 52] 



In the summary of results of experiments with potatoes, it is 

 said that potatoes deteriorate rapidly under ordinary cultivation, 

 and It is necessary lo frequently change seed in order to keep 

 them in their |)ristine purity and excellence. We need go no 

 farther than Ireland, with its worn-out variety of the Champion 

 potato, for a case in point. As a treatment for apple-scab 

 (Fiisicladiiimdciidriliiiim, Fckl. )itis recommended tothoroughly 

 spray the trees, before growth begins in spring, with copper 

 sulphate solution. This should be followed with an ap]ilication 

 of Bordeaux mixture as soon as the blossoms have fallen. In a 

 wet season two or three more dressings w ill be necessar)' to pro- 

 duce the best results. The addition of Paris green to the second 

 and third .applications will keep the codlin-moth and the canker- 

 worm in check. A caution is given never to spray with 

 arsenites when fruit-trees are in bloom, or the bees «ill lie 

 killed. 



An attempt at a partial restoration of the geography of the 

 world in Cretaceous times is made by Dr. ¥. Kossniat, of 

 \"ienna, in the May number of the AWordi of the Indian 

 Geological Survey. He recognises the broad distinction of 

 Atlantic and Pacific faunal pro\-inces in Cretaceous times, a dis- 

 tinction very marked in the northern hemisphere, but disappear- 

 ing to the south of the then existing Indo- African continent. 

 The Cretaceous beds of Southern India form the clearest link 

 between the two ; combining in their fauna the typical Pacific 

 forms with others characteristic of Central ICurope. Their con- 

 nection with thv latter area was a roundabout one, through 

 Natal, Angola, and the Atlantic, by which they are also linked 

 to the Cenomanian and Uanian deposits of Brazil. The fauna 

 of Northern India is quite distinct, and must lie regarded as 

 inhabiting the easterly termination of the Meclilerranean pro- 

 vince, one which was an almost isolated area, though to the 

 westward, in the Gosau beds and those of Southern France, we 

 can see evidence of a connection with the Atlantic. Further 

 west a similar fauna is found in the Antilles, and extends even 

 into the Pacific region in Peru. The fauna of North America 

 shows close aflinities with that of Kurope, and less marked 

 relations to that of Southern India, while it stands .sharply con- 

 trasted with that of the Pacific side of the continent. The 

 upper Cretaceous beds of Atlantic facies are found, however, 

 to extend into Briti-sh Columbia and Queen Charlotte's 

 Islands, and there rest upon lower Cretaceous beds of Pacific 

 facies. The American continent must thus have existed as two 

 great insular masses forming a barrier between the two great 

 marine i)rovinces, broken across by two arms of the sea. The 

 author jnuposes constructing a chart to embody these con- 

 clusions. 



Tn.\ r <piile a considerable number of bacteria exist which 

 will only gro« at such high temperatures as lie lietween 50° and 

 70° C., was first shown by (dobig ; but his investigations only 

 succeeded in demonstrating them in the .superficial layers of soil. 

 Now, however, we know that such bacteria are to be found in 

 river water and mud, in foeces, and at considerable depths in the 

 soil. (Juite recently Dr. Lydia Kabinowitsch has made ex- 

 tensive researches in Dr. R. Koch's laboratory on these so- 

 called thermophilic bacteria, and their distribution appears to 

 be much wider than was at first supposed. Thus Dr. Kabino- 

 witsch has found them abundantly present in .surface soil col- 

 lected from various parts of Berlin ami other places in Germany; 

 they were also discovered in freshly-fallen snow, indicaling their 

 probable presence in the air, and large numbers were obtained 

 from river Spree water, although they were not found in the 

 Berlin water supply ; they were also isolated from excre- 

 menlitious matter derived from horses, cows, g<iats, dog«i 

 rabbits, ducks, parrots, some fish and other cold-blooded 

 animals, such as the frog and python. These bacteria are also 



