April 3, 1890] 



NATURE 



521 



pumped into a wooden tank 10 feet above the hatchery, holding 

 1200 gallons. Thus a constant circulation of the water in the 

 tanks is maintained. The water is pumped from the sea at high 

 water, and left to settle some days in a storage reservoir before 

 use ; each hatching tank has room for twelve wooden trays, 

 measuring 16 inches by 10 inches, by 9 inches in depth, with a 

 canvas strainer at the bottom to prevent the eggs escaping. The 

 Society aims at recording observations respecting marine life, 

 and the improvement of the fisheries of the United Kingdom, 

 by the artificial propagation of marine fishes and Crustacea, by 

 the pursuit of scientific observations and investigations respecting 

 the natural history, habitat, migration, spawning food, and the 

 effect of weather, temperature, and conditions of the water, cur- 

 rents, tides, light, and darkness upon the fauna of the sea ; by the 

 protection of young fish, and the introduction of practical appli- 

 ances for the capture of mature fish ; by endeavouring to ascer- 

 tain the best methods of transporting fish in a fresh condition, 

 and economically preserving them. By admitting fishermen 

 into the Society, at a nominal subscription, they hope to get 

 numerous observers and collectors from amongst those who 

 spend their life reaping the harvest of the sea. 



At the last meeting of the Societe Chimique de Paris a paper 

 by M. Meslans was presented by M. Moissan, announcing the 

 isolation of fluoroform, CHF3, the fluorine analogue of chloro- 

 form, CHCI3. A brief abstract of this preliminary communica- 

 tion will be found in the Chemiker Zeitung for March 26. 

 During the course of the work recently published concerning 

 propyl and isopropyl fluorides, M. Meslans had occasion to study 

 the action of silver fluoride upon iodoform. The result of this 

 action was found to vary according to the conditions of experi- 

 ment, liquid products being obtained under certain conditions, 

 and gaseous products under others. The end result, however, 

 was always the production of a gas, which turns out to be 

 fluoroform. Chloroform, as is well known, is readily attacked 

 by a warm alcoholic solution of potash, potassium chloride and 

 potassium formate being produced : CHCI3 -}- 4KOH - 

 H . COOK + 3KCI + 2H2O. It is interesting to learn that 

 fluoroform behaves in precisely the same manner, for the gas is 

 decomposed by either aqueous or alcoholic potash with formation 

 of fluoride and formate of potassium. On being heated to 

 redness in a glass tube fluoroform is also decomposed, with 

 production of gaseous silicon tetrafluoride and a deposit of 

 carbon. The gas is only very slightly absorbed by water, but 

 it dissolves readily in chloroform or alcohol. Fluoroform has 

 also been prepared by substituting chloroform or bromoform 

 for the iodoform used in the first experiments. 



At the same meeting M. Chabrie reported that he also had 

 obtained a gas by heating silver fluoride with chloroform in a 

 sealed tube, which yielded potassium formate with potash, and 

 was evidently identical with the fluoroform described by M. 

 Meslans. The density of the gas was determined, and found to 

 be 2 '4 14. Fluoroform possesses the density 2*43, so there can 

 be no doubt as to the identity of the gas. Although so readily 

 attacked by warm potash, it was found that a cold alcoholic 

 solution of potash was almost incapable of acting upon it. 



M, Moissan also presented another interesting paper in the 

 names of MM. Guenez and Meslans, describing the isolation of 

 fluoral, CF3.CHO, the analogue of chloral, CCI;,.CIiO, the 

 tri-chlor derivative of common aldehyde, CH3 . CHO, and the 

 hydrate of which has recently become so famous as a drug. 

 Fluoral, like fluoroform, is a gas, and has been obtained by 

 heating silver fluoride with anhydrous chloral. The gas dissolves 

 to only a very slight extent in water, but is absorbed by aqueous 

 or alcoholic potash with formation of formate and fluoride of 

 potassium, thus again resembling its chlorine analogue. To 

 complete the proof of its identity, the density of the gas was 



determined and found to agree very closely with the calculated 

 density of anhydrous fluoral. 



The additions to the Zoological Society's Gardens during the 

 past week include two Ring-necked Pheasants {Phasianus 

 iorquatns (J ? ), British, presented by H. R. H. the Prince of Wale?, 

 K.G. ; a Chacma Baboon (Cynoccp/talus porcarius ?) from 

 South Africa, two Indian Pythons {PytJion molurtis) from 

 India, five Common Boas {Boa constrictor) from South America 

 deposited ; three Red-footed Ground '6o^\xx&\%{Xerus erythropm) 

 from West Africa, two Himalayan Monauls {Lophophorus 

 impeyanus 9 9) from the Himalayas, two Diuca Finches 

 {Ditica grisea), a Black-chinned Siskin {Chrysomitris barbata)i 

 two Field Saffron Finches {Sycalis arvensis), an Alaudine Finch 

 {Phrygilus alaudinus) from Chili, purchased; a Hog Deer 

 {Cervus porcinns i ), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Objects for the Spectroscope. 



Sidereal Time at Greenwich at 10 p.m. on April 3 = 

 I oh. 48m. 43s. 



Remarks. 



(i) This is the well-known nebula 97 M, near 3 Urste 

 Majoris. In the General Catalogue it is described as "a 

 planetary nebula, very bright, very large, round ; at first very 

 gradually, then very suddenly brighter in the middle to a 

 planetary disk ; 19 'os. in diameter." Lord Rosse's draw- 

 ing of the nebula indicates a very complex structure. I 

 examined the nebula recently with Prof. Lockyer's 30-inch 

 reflector at Westgate-on-Sea, but was unable to see ail the 

 details shown in Lord Rosse's drawing. The nebula appeared 

 to be a large disk, ill-defined at the edges, and equally illumin- 

 ated, with the exception of two darker disks situated diametric- 

 ally opposite to each other, each being about half a radius in 

 diameter. Dr. Huggins observed the spectrum in 1866, and 

 found it to consist of bright lines. The two lines near W 500 

 and 495, and possibly a little continuous spectrum were re- 

 corded. On the occasion above referred to I saw the three 

 usual nebula lines and the hydrogen line at G, but was unable 

 lo continue the observations on account of clouds. In further 

 o'iservations, additional lines ought to be looked for, and the 

 character of the chief line near K 500 particularly noted, as in 

 the case of the nebula G.C. 2102, given last week. 



(2) A star of Group II. Duner states that the bands 2-8 are 

 well seen, but that they are not strongly marked. It is im- 

 portant to secure further observations of stars like this, as there 

 may very well be other differences besides the weakening of the 

 bands as compared with those in which the banded spectrum is 

 more fully developed. 



(3) This has a fine spectrum of the solar type (Vogel). The 

 usual differential observations are required. , 



(4) The spectrum of this star is a typical one of Group IV. 

 (Vogel). The hydrogen lines are probably therefore very thick, 

 and the metallic lines very thin, if visible at all. The thicker 

 the hydrogen line the hotter the star, and the higher therefore its 

 place on the "temperature curve." 



(5) Vogel and Duner agree in describing the spectrum of this 

 star as a very fine one of Group VI. The three carbon bands are 

 stated to be visible, but the intensity of the band near \ 564 re- 

 latively to the others is not given. This point should therefore 

 receive attention. The secondary bands 4 and 5, and possibly 

 2 and 3 are visible. It is interesting to note that this star shows 

 considerably more detail than several brighter ones of the same 

 group. 



