April, 1879. the winged female, back view ; greatly magni-1 tied, aa uie natural uze m shown in the short line on the left The phylloxera spreads in several ways. The wingless inseot is said, by Prof. Riley, to travel over the surface from vine to vine, or beneath the ground where roots interlock ; while in the winged form it may fly or be carried by the wind 16 or 20 miles, and, under exceptional conditions, even more. Through man's agency by oommerce in plants or cuttings, it may bo carried indefinite distances. Therefore some governments, as the Australian, Algerian, Italian and German, have prohibited the introduction of vines from infested regions. Signs of the disease are given by Prof. Kiley as follows: "A vine attacked by phylloxera has the more 6brous roots covered with little nodosities or swellings, and a careful examination of the swellings during the grow ing season will disclose numerous yellowish lice of different ages and groups of brighter yellow eggs, barely visiblo to the naked eye. The swellings in time rot, and the lice settle on the larger roots. Vines that aro more susceptible to the disease gonerally show oxternal signs the second year of attack, in a sickly yellowish ap pearance of the foliage and in stunted growth ; while the third year they frequently perish, when on examination the lice are no longer to lie found ; they have left or died, and all the liner roots have decayed and wasted away." The time to make the examination is as soon as the first signsof decreasing vigor appears. It is true, as a correspondent argues on another page, that sick vinos may arise from other cause than the phylloxera, but it should be looked for, and for those who are not sharp sighted, we can but offer, as wo have done before, the use of our eyes and mioroscope, to any reader who sends us suspected vines. iNTKKEKTINCl Kxi'KRIMKNTH IN ilKUAHII TO SrONTANKOVH CoMBtlHTION. K. Bing, of Riga, has experimented with different materials; wad ding, raw llax, hemp, the waste from silk, wool and cotton spinning as well as spongo, anil fin ally wood dust as found in any cabinet-maker's shop. They saturated with various fluids, via., oils, fresh and in a gummy stato ; turpentine, Iietroleum, various varnishes, etc. All the tibrous materials took fire when saturated with any of these oils or with mixtures of the same. Sponge and wood dust, on the contrary, proved to be entirely harmless. Combustion ensuod moat rapidly with 17 grains of waddiug ami i7 grains of a strong od varnish, in 37 minutes; while 200 grains of wsahed cotton waste, of whioh a portion was saturated with 750 grains of strong oil varnish and the remainder wrapped about it, required almost I t hours. Thesu ma terials were placed in a well-sheltered spot and subjected to a heat of from 18 to 40 C. Milk did not Dame up, but slowly charred. Hmall quantities seem to take lire sooner than large. Snow Illumination. -During a recent snow storm, in the early afternoon, an interesting ex periment was tried in Paris. At the moment when the sky was darkened by snow, the elce. trio lamps were lighted in the square of the Theatre Fraucais. The reflection of the light from the snow-Hakes immediately dispelled the darkness and produced a very pleasing effect It in proposed to try a similar experiment in misty weather, and if the light can penetrate even to the distance of 20 meters (6.1.0 feet), .lablochkoff lamps will be established at points where the passing is most frequent. 1m Mon ilm. Klhtho-Chmii'ai. Action Unimxh I'm "ml In a series of about AO experimenU, each of which continued for several hours, ami du ring whioh pressures of 100, 200, 300, etc, at ii'iapheree were maintained, A. Bouvet found the following laws: I. The decomposition of water by a current is independent of its pres sure. 2. The quantity of electricity necessary to decompose a given weight of water ia setuu bly the same, whatever may be the pressure. The laws are in perfect aocordance with the mechanical theory of beat THE WEST SHORE. TBI tsthmits rtv DARfJEN 0AKAL "3 LIGHT AND LITE. The old problem of a canal cutting the Isthmus of Uarion is now assuming new life through the persistent inquiry of the French. The results attained by the last body of French engineers sent out to study tho feasibility of the canal have been published. Their report is being followed up by French writers who take up the resultant benetita of the canal and adorn them with rosy colors. The latest of these views is that of the Kronomulr Fro mi This journal has been figuring the sailing time be tween different commercial centers, which court the Chinese trade, and the commits tions sro found to bo vastly in favor of our Kastcrn seaboard over Kngland. Our Fastem merchants anil manufacturers are pushing their Kngliah competitors dose to tho wall in many porta of the world, and thoy will make haste to avail themselves of any advantages which they may find in assailing the eastern coast of Asia with their merchandise. The French journal, to which we have alluded, gives statistics showing the setual differences 111 distances and time lietwecu voyages from the English channel to Pacific and Chinese ports, ana from New York to the same poiuta. The advantages are in favor of the latter, being to San Frauuisoo, Callao, Valparaiso sod Sandwich Islands, four snd a half days, or from .'IJ , to H" and 8' days, or 7, to Shanghai. If an isthmus canal be opened, the difference fur sail ing vessels would be 24 days, or from XI to M from New York to the four places named, ami 22) days, or 28, to Shanghai. Tho aver age gain to New York veasuls would be 2,000 milos, or 10 dsys over Kuglish and French com petitors. Attention is then called to the in creased use of steamers since the upehiiig of the Sues ceual. The same result would follow by the isthmus route. The difference then in favor of New York for steamers, which is now very .....II ulluli ..,,1 1., .., U n.o...., h ... .....j ,,, to '&, would, with the canal, lie, to San rrau cisco, 12 out of 29 days, 41 .; Callao, 12 out of 21, or 87; Valparaiso, 12 out of 27, or M fc the Sandwich Islands, 12 out of 3A, or 34,. aa advantage of 44 on the average for New York, simply doubling the commercial advantages to the United States with the Pacific. It will be greatly to tho glory of the French engineers and capitalists if they succeed at Hum n, where so many commercial Miwers, in cluding our own governmeut, have ciplnred and turned hack in dismay. Although, n should dislike, ou general principles, to see any foreign nation win control of any artery of Ma, meroe which will he so iniHirtant to this country as the isthmus canal, still if ths pro ject goes much longer by defsult by our inao tivitv, their can In nu cause for complaint. Perhaps it would he as well to hsve tho French own the canal as any other foreign iwsr, and so long ss ws get the commerc ial Innelit, per' haps we can afford to let the Frem h raise the money and reap the glory. Ikon sMi Siui on. Some time ago there was taken from the ground, we forget iu what locality, a metallic ingot having the look of iron, liut, notwithstanding lU long contact with im.iature, showing no trace of osiilatioii. Prof J. law renoe Smith, who lately analysed It, lound it to be a sillicide of iron, containing 17 of sdlicide. This compound is so inalterable that it will remain without change 111 nitric acid of I 40 density, or in bromine. Hydrochloric acid affects it somewhat The history of the ingot is not known, but it thought to owe Its je lata to son aootdeol in the manufacture of iron M. iHuibree, oommeoUng on NhlM French Academy, staled that, notwithstanding vary snort, it had wit betm found poeeibisto incorporate mora than sight per mot uf allien with iron. M. Haani Claire IhrvUla wsa struck with the aiialogy of the product la qoeelw to the silhcide of mangaaose prodaosd some years ago by M. Bruannr. WmwwiiV C'icwuerr,. Ths question ss to how life is affected by the different colors of the sieetnim haa at various times engaged attention, and plant lifs has apparently been more studied In this respect than animal. Two distinct series of researches lately deaorilwd to the French Academy seem to afford some fresh insight into the matter, snd it is interesting to eniiqiare them together, One series, by M. Bert, was on plants; the other, by M. Yung, ou the eggs of certain animals. M. Bert kept plants within a glass trough inelosure, containing au alcoholic solu. tion of ehloroiihyl (very frequently reoswsd), and csposnl them thus in a good diffusa light The solution, which waa very weak, and in a very thin layer, intercepted little more than the characteristic region of the red In the spectrum. This excluded part then, waa proved to he the iudiaieueable jtart of white light for the plsnta immediately ceased to grow, and before long died. It ia in this rod region aa M. Tlmirigsali has lately shownl tbst the greatest reduction ol carlsinie acid takea place. If red raya are kept from the leaf the iilaut can no longer increase its weight, it ia reduced to oonaiiming reserves previously accumulated, eshausla itself, and dies. This p.ni of the spectrum, however, though necessary, Is not sufficient Behind red glass plant- may 110 duubt llvu long, but they get excessively elongated and slander, and then leaves become narrow and little colored. This is owing to the slajeliee of the blue violet rays. Thus each region of the -p. . triim "nutalns parts that plsy an active mlr in the life nf planta. Now turn to animals. M Yung has espsrC mrnted during three yesrs on the effect nf dlf (urent sielrsl colors on the development of the eggs of frogs (tho common frog snd the edible Irogl, ol trout sun ol fresh wster snails It waa found that violet light favored the devalop inent very remarkably , blue light ...00 a nest ill this respe, t, and la followed by yellow light and white light Iwhlch two gave nearly similar effects). Ou the other hand, red snd green sp pear to lie positively injurious, lor It waa lound impossible to get complete development of the egga 111 these colors. Ilsrkneas does not prevent development, but contrary to what some hsve sflirined, retards it. Tadioloe nf the same sise, and subjected to the same physical condttiuna previous to eisninent, died mora quickly of inanition when deprived of food In violet and blue raya than in the others l,nmlim 7'ims F.rrwr 0J Fi rs ran u ok YauttANi.r, (i now ill. I luring last summer, I'aateur, a, cording to ComaVs ,siwms, mad, anine interest lllg aiieriineule on the r (feet of i , etriclly on vegetable and froit growths Ou Ilia 4th ol August, he en. I.N,, . I some vine Beta III hot I. Is. slm.at hermetically sealed. The gratm ripened als.ut October lllth. I. rapes that had ripened in the open air fermented In boa lb in m hours, in a temperature varying between 2.1' and .Hi (77 to M I 1. bat thi that rlpennd under glsaa remained unchanged. This result, which hail I-en predicted by Pasteur, lends strong confirmation to hia views. Again, on July "HI., W77, M Cadi planted three kernels of maite under each of two taatl glsaaas. The weight aj the kernels, the kind ul earth, snd the quanta, of wster supplied dally, were equalised aa nearly aa possible. On August 1st, ths kernels sprouted I luring two daya the growth waa nearly the same under both glasses, flu the third day the plants in eleotrlssn air began to develop nwifs rapidly than the other. On August Intl., ths following measurements were taken, from Iks base of the stalk to the tstremily of the upper leaves Plants in alntnesd air, 17 em. (II AO ia ); plants In ordinary air, H esa. 1 1 15 in. ). 1 iiiniasu, fuf the Hret Mass sines her ad mission tii the Causa, waa unrepresented la Use Hones of ItepreaaaUtsvss al the opening of the special session.