Feb. I, 1877] 



NATURE 



303 



pied Dr. Roberts's attention has also occupied mine, and that 

 my results are identical with his. 



In some of the experiments the procedure described by Dr. 

 Roberts was accurately pursued save in one particular, which has 

 reference to temperature. Small tubes with their ends finely 

 drawn out were charged with a definite amount of caustic pot- 

 ash, and subjected for a quarter of an hour to a temperature of 

 220" Fahr. They were then introduced into flasks containing 

 measured quantities of urine. The urine being boiled for five 

 minutes, the flasks were hermetically sealed during ebullition. 

 They were subsequently permitted to remain in a warm place 

 sufficiently long to prove that the urine had been perfectly sterilised 

 by the boiling. The flasks were then rudely shaken so as to 

 break the capillary ends of the potash tubes and permit the 

 liquor potassa: to mingle with the acid liquid. The urine thus 

 neutralised was subsequently exposed to a constant temperature 

 of 122"^ Fahr., which is pronounced by Dr. Bastian to be spe- 

 cially potent as regards the generation of organisms. 



I have not found this to be the case, for ten flasks prepared 

 as above described towards the end of last September, remained 

 perfectly sterile for more than two months. I have no doubt 

 that they would have remained so indefinitely. 



Three retorts, moreover, similar to those employed by Dr. 

 Bastian, and provided with potash tubes, had fresh urine boiled 

 in them on September 29, the retorts being sealed during ebul- 

 lition. Several days subsequently the potash tubes were broken 

 and the urine neutralised. Subjected for more than two months 

 to a temperature of 122° Fahr. they failed to show any signs 

 of life. 



These results are quite in accordance with those obtained by 

 Dr. Roberts. His potash tubes, however, were exposed to a 

 temperature of 280° Fahr., while mine were subjected to a tem- 

 perature of 220° only. 



With regard to the raising of the potash to a temperature 

 higher than that of boiling water, M. Pasteur is in advance both 

 of Dr. Roberts and myself. In a communication to the French 

 Academy, on July 16 last, M. Pasteur showed that when due 

 care is taken to add nothing but potash (heated to redness if 

 solid, or to 110° C. if liquid) to sterilized urine, no life is ever 

 developed as a consequence of the alkalisation. ^ 



M. Pasteur has quite recently favoured me with sketches of 

 the simple, but effectual apparatus, by means of which he has 

 tested the conclusions of Dr. Bastian. Since his return from his 

 vacation at Arbois, he has carefully gone over this ground with 

 results, he reports to me, not favourable to Dr. Bastian's views. 



I may add that I have by no means confined myself to the 

 thirteen samples of urine here referred to. The experiments 

 have already extended to 105 instances, not one of which shows 

 the least countenance to the doctrine of spontaneous generation. 



It gives me pleasure to refer to the skill and fidelity with 

 which here, as in other cases, Mr. Cottrell has carried out my 

 directions. 



OUR ASTRONOMICAL COLUMN 

 The New Star in Cygnus.— In No. 2,115 of the Astrono 

 inische Nachrichten, Prof. Schmidt publishes the results of his 

 observations on the intensity of light exhibited by this star be- 

 tween November 24, the date of its discovery, and December 15, 

 when it was last perceptible to the naked eye. Having laid 

 down his estimates of magnitude graphically on a large scale, 

 he reads off therefrom the magnitude for every sixth hour, the 

 differences showing a marked uniformity except about November 

 28, when the diminution of brightness was much more rapid. 

 The magnitudes at midnight are as follow : — 



Nov. 24 ... 2-97 



„ 25 ... 3-03 



„ 26 ... 3-14 



„ 27 ... 3-38 



„ 28 ... 4'o6 



„ 29 ... 4-74 



„ 30 ••• 5-06 



Dec. I ... 5*27 



„ 2 ... 5-47 



M 3 ••• 5-65 



„ 4 ... 5-81 



„ 5 ... 600 



„ 6 ... 6-i6 



„ 7 - 6-32 



Dec. 8 ... 6"44 



„ 9 ••• 6-55 



,, 10 ... 6"64 



„ II ... 671 



„ 12 ... 679 



„ 13 ... 6-86 



„ 14 ... 6-92 



In the forty-eight hours following November 27'* iS^ there was 

 a diminution to the extent of nearly i.^m. It is remarked that 



' That alkaline liquids are more difficult to sterilise than acid ones was 

 announced by Pasteur more than fourteen years ago. See AmutUs de 

 Chimie, 18C2, vol. Ixiv. p. 62. 



on the night of discovery its brightness was such as to render its 

 near neighbour, 75 Cygni, invisible, while on December 14 and 

 15, 75 Cygni (6'4m.) in its turn nearly obliterated the new one ; 

 at 10 P.M. on the latter date it was only by great exertion of the 

 eye that a trace of the star could be discerned. Prof. Schmidt 

 did not remark any decided change of colour : it was at no time 

 decidedly of an orange tint, but less ruddy than 7, e, and f 

 Cygni, yet of a full yellow, 5 "6 to 5 "8 on his scale. 



The curve resulting from the Athens observations accompanies 

 Prof. Schmidt's description, and for comparison with it similar 

 curves are added to show the law of diminution to the limit of 

 unassisted vision, in the cases of the so-called new stars of 1848 

 (Hind, April 27) and 1866 (Birmingham, May 12). The descent 

 was slowest in the former case and quickest in the latter, but the 

 curve for the star of 1848 appears to be drawn from a small 

 number of observations. Prof. Schmidt assigns for the interval 

 between discovery and disappearance to the unaided vision, 

 twenty-five days in 1848, nine days in 1866, and twenty-one days 

 in 1876; the writer is able to state that the star of 1S48 was 

 just perceptible without the telescope as late as May 27, four 

 days after the termination of Prof. Schmidt's observations and 

 thirty days after its discovery, and there was a decided check in 

 the star's descent between May i and 6 ; on May i it was a 

 little less than 20 Ophiuchi, and on May 6, certainly a little 

 brighter than that star. On April 29 it was so nearly equal to 

 V Serpentis that close attention was necessary to decide which 

 was the brighter ; v was found to be in a very trifling degree 

 superior. 



Variable Components of Double Stars. — A suspicion ot 

 variability in the small companion of S Cygni has been enter- 

 tained by several observers. Prof. Secchi, among others, having 

 remarked that the star has appeared single at times when the 

 atmospheric circumstances would not afford an explanation. 

 But the case of 72 Ophiuchi, No. 342 of the " Pulkova Cata- 

 logue " of 1850, is a much more suspicious one. The discoverer, 

 M. Otto Struve, says, ** I have very often looked at this star, 

 and have many times noted it single. Yet on three occasions I 

 have seen it double, always in about the same direction, and at 

 a distance of i"*5. I do not know how to explain these discord- 

 ances, except on the supposition that the satellite is very variable." 

 Secchi found the star single at the epochs i856"53 and 185771 ; 

 at 1857 57 a doubtful companion was noted in the direction 

 3450-9, but at the epoch 1859 "61 he records it "certainly double, 

 and well separated," the measures giving the position 3° 75, and 

 distance o" '608, This star does not occur in the more recent 

 revision of the Pulkova list, by the Baron Dembowski, 



To such cases may be added those of a Herculis and jS Cygni, 

 where the companions do not vary to such an extent as to cause 

 the objects at times to appear single. 



The Binary Star 7 Centauri. — While awaiting further 

 measures of this fine double star, it may be remarked that 

 admitting the measures of Sir John Herschel in 1835-36, to 

 require an alteration of 180°, in order to render them com(jarable 

 with those of Capt, Jacob and Mr, Powell, the latest published 

 angle measured by the latter observer in i860, indicates a motion 

 in a retrograde direction of upwards of 160° between 1835 '85 and 

 1 860 -68, the distance having increased about o"'4. The star will 

 be in all probability one of comparatively short period, and, as 

 such, deserves attention at the hands of southern observers. The 

 alteration of 180° in Sir John Herschel's measures is quite justi- 

 fied by the near equality of the stars. 



The Minor Planets, — M, Perrotin, of the Observatory at 

 Toulouse, met with a small planet on January 10, in a region 

 of the sky where it is probable that Nos. 77 and 149, 

 Frigga and Medusa, are at present situated, and the same 

 planet was detected some ten days later by Prof. Peters at 



