'OV. 2, 



1876J 



NATURE 



15 



id the earth's heliocentric longitude being I5°'3, the inferior 

 injunction of the assumed intra- Mercurial body with the sun 

 rould have occurred on the morning of Stark's observation. 



The Fourth Comet of 1857.— The best determined period 

 revolution of a comet, exceeding in length the period of the 

 *Comet which appears to be associated with the August stream 

 of meteors, is that of the fourth comet of 1857, discovered by 

 Prof. C. H. F. Peters at Albany, U.S., on July 18, by Dien, 

 at Paris, on the 27th, and by Habicht at Gotha, and Donati at 

 Florence on the 30th of the same month. It was observed with 

 the great refractor at the observatory of Harvard College till 

 October 21. These dates include an interval of from about one 

 month before to two months after the perihelion passage, or an 

 arc on the orbit of 145°. A very complete discussion of the 

 observations was made by Dr. Axel Moller, whose masterly 

 investigations relating to the motitn of Faye's comet have led 

 to such accurate prediction of its apparent track in the heavens 

 at recent returns ; the period he assigns is 2347 years. A 

 similarly rigorous calculation led Dr. Hans Lind to a revolution 

 of 243-05 years, and there are ellipses of nearly the same length 

 of period by other computers. 



If we examine the path of this comet through the planetary 

 system we soon discover that it passes near to the orbit of Venus. 

 Employing the elements of Axel Moller, a strict calculation 

 shows that in heliocentric ecliptical longitude 24° 54', the dis- 

 tance between the two orbits is less than 0*023 of the earth's 

 mean distance from the sun. I: may therefore be reasonably 

 concluded that it is to an actual near approach of the comet to 

 Venus about this point that the present form of orbit is due. 

 The comet's perihelion distance is 0747, the aphelion distance 

 75 -SS- 



BIOLOGICAL NOTES 



Pock-Lymph. — The efficacy of pock-lymph has been attributed 

 by several observers to the presence of small organisms of the 

 nature of Micococcus. M. Hiller has recently studied this subject 

 (Ccntralblatt fur d. Med. Wiss. ), and from 6,840 separate inocula- 

 tions, he finds that the degree of activity of the lymph and the 

 proportion of micrococci present do not correspond ; on the 

 one hand, the development of the organisms was often at its 

 greatest when the action of the lymph was falling off, and on the 

 other, lymph was often active, though no bacteria were per- 

 ceptible in it. Fresh diluted lymph having been put in vertical 

 tubes in a freezing mixture, and slowly thawed after freezing, the 

 upper half gave on inoculation, 41-4 per cent, positive results, 

 the lower half, 63-8 per cent. It appears from this that the 

 poison is associated with the solid? constituents more than with 

 the liquid. Boiled lymph was, without exception, inoperative. 

 The addition of i to 4I per cent, carbolic acid merely weakened 

 the contagiousness of pock-lymph, while addition of glycerine 

 left it unaltered. Strong dilutions weakened the action, while 

 condensations exalted it ; with evaporation, the percentage of 

 favourable cases was increased about a half. In coagulated parts 

 produced in the lymph, the active element was present in great 

 quantity. Perfectly dried lymph is [also active in high degree ; 

 hence we may infer that the communication of pox may occur 

 by means of the crust and scurf of pustules which are rubbed 

 off and float in the air. Inoculation with the blood of persons 

 that were successfully inoculated proved inoperative ; so also 

 were the fresh contents of the bladders, seven days after inocu- 

 lation. It is inferred that the cow-pox ferment is not contained 

 in the blood, or not in the active state ; and that very probably, 

 also, the blood is not itself the seat of fermentation and repro- 

 duction of the poison. 



Algoid Swarm-Spores.— If vessels of water containing alg£e 

 are placed in a room where they are lighted only on one 



side, swarm-spores are generally found to collect at the 

 side turned towards the window, more rarely on the oppo- 

 site side. If they are present in considerable number, they 

 often become arranged in peculiar cloudy forms ; network, 

 rays, tree-like branched figures, &c. The phenomenon has 

 been frequently studied, and has been always regarded as an 

 action of light, causing the living swarm-spores to move towards 

 it or withdraw from it. After a long investigation of the pheno- 

 mena, M. Sachs has come to a different conclusion. He con- 

 siders that these groupings of zoospores are not phenomena of 

 life, inasmuch as quite a similar process is found to occur with 

 emulsions of oil in alcohol diluted with water ; also that the light 

 either does not at all participate in the action, or does so only 

 indirectly, for all the phenomena may be reproduced in dark- 

 ness. The accumulation of spores and the cloud-like figures are 

 rather due to currents produced by differences of temperature in 

 the water. M. Sachs's experiments are described in Flora, 

 1876, No. 16. 



Diseases Germinated in Hospitals. -Several observers 

 have remarked on the presence of globules of pus and micro- 

 scopic algse in the air and on the walls of hospitals. Some 

 interesting facts of this order have recently been communi- 

 cated to the French Societe de Biologic, by M. Nepveu of 

 the laboratory of La Pitic. A square metre of the wall of a 

 surgery-ward, having been washed, after two years without 

 washing, the liquid pressed from the sponge (about 30 gr. ) was 

 examined immediately after. It was Somewhat dark throughout 

 and contained micrococcus in very great quantity (fifty to sixty in 

 the field of the microscope), some micro-bacteria, a small number 

 of epithelial cells, a few globules of pus, some red globules, 

 and lastly a few irregular dark masses and ovoid bodies of 

 unknown nature. The experiment was made with all necessary 

 precautions ; the sponge employed was new, and carefully 

 washed in water that was newly distilled. Facts like those 

 referred to make it easy to comprehend how the germs of a large 

 number of diseases occur in the air of hospitals, and how the 

 latter may readily become centres of infection. The same con- 

 ditions, though in less degree, may sometimes be met with in 

 private life. 



Marine Mosses. — M, Gisard lately showed to an audience at 

 the Congress of learned societies at the Sorbonne, specimens of 

 marine mosses growing on a madrepore placed in an aquarium, 

 since January, 1872. They produce every year, in spring, phe- 

 nomena of fructification, consisting of urns of a superb nacreous 

 colour, growing at the ends of beautiful green filaments, then be- 

 coming detached and rising to the surface of the water. He cited 

 the following fact as showingthevitality of certain marine plants. 

 On May 13, 1875, a parcel of alga; which had been taken from 

 an aquarium and dried several months in the sun, was placed in 

 sea-water, and developed a magnificent green plant of ribbon 

 form. In February and March, 1876, there were formed on the 

 border of the ribbon sparse filaments carrying rounded urns of 

 variegated colour, which became detached, and rose to the sur- 

 face, giving rise to green plants. 



Notes from St. Petersburg.— At the last meeting, Oc- 

 tober 18, of the Zoological Section of the St. Petersburg Society 

 of Naturalists, Prof. Wagner gave some information as to his 

 recent researches made in the Solovetsky Bay of the White Sea. 

 The special aim of them was to throw some light on the causes 

 which determine the use in certain organisms, as for instance the 

 hydroids, of two different modes of reproduction, sometimes by 

 gemmation, and sometimes with the help of special organs. 

 Without coming to any decided conclusions (the researches 

 having to be continued) M. Wagner pointed out, as one possible 

 cause of this difference, the influence of different nutrition which 

 generally so greatly influences the reproductive functions. M. 



