6o6 



NATURE 



[October 20, \\ 



object is exactly identical in position with that of the old 

 nucleus. 



M. Seraphimoff also mentions that an examination of all 

 photographs, drawings and descriptions of this nebula shows 

 that the central part was very seldom referred to as a small star. 

 In the year 1885 numerous observations {Astr. Nachr., vol. 

 cxii.-cxv. ) showed that the central portion had a different appear- 

 ance to what it now has ; at the present time the two small stars 

 appear equally bright and sharp, and this has been corroborated 

 by Profs. Backlund, Belopolsky and Morin. 



That the central portion of this great nebula is variable there 

 can be little doubt, but up to the present time only very small 

 differences of intensities have been recorded. 



Prof. Pickering, in a Harvard College Circular, No. 34, states 

 that a comparison of photographs of the nebula taken with the 

 8-inch and ii-inch Draper telescopes on September 20 and 21, 

 1898, with similar photographs taken in 1893-96, fails to show 

 the new stellated appearance. 



Atlas of Variable Stars. — In a recent number of the 

 Astr. Nachr. (No. 3523), Dr. J. G. Hagen describes the 

 arrangement of a new atlas of variable stars, which we hope will 

 soon be published, as it promises to be a very useful addition to 

 an astronomical observatory. When completed the chart will 

 consist of five series, the first three showing, on separate sheets, 

 the positions and neighbouring . stars of variables with faint 

 minima ; the fourth series of charts is for variables observable 

 with small instruments ; and the fifth, for naked eye variables. 

 The sample chart accompanying Dr. Ilagen's notice gives one 

 an idea of the completeness of the work undertaken. The 

 zones included in the first three series are - 25° to 0°, 

 0° to + 25°, and + 25° to 90°, and will cover altogether 150 

 charts. These charts include a field of one square degree, with 

 an inner square of half the sides. On the outer side of the small 

 square only stars of the BD are inserted. In the inner square 

 all stars are inserted which appear in a 12-inch with a magnifier 

 of 45 and a measurable field of o°75. 



The variable, with one exception, on each chart is situated in 

 the middle, so that the observer will be able directly to recognise 

 in his field of view which of the stars is the variable in question. 



Each chart, further, gives the coordinates of the variable for 

 1900, with the annual movements, and, in addition, the colour, 

 type of spectrum according to Secchi's classification, and the 

 magnitudes at maximum and minimum. We may mention 

 that each chart will be mounted on good stiff cardboard, and 

 being of a handy size can be held by or placed close to the 

 observer at the eye end of the telescope. 



In conclusion, it must be remembered that the publication of 

 this fine series of working charts is a very costly affair, and would 

 probably not have been accomplished had not the benevolent 

 Miss Catherine Bruce taken her usual interest in the progress of 

 astronomical science, and tendered considerable financial help 

 to further the printing of them. 



Reminiscences of an Astronomer.— Prof. Simon New- 

 comb continues his reminiscences in the third of a series of 

 articles to the October number of the Atlantic Monthly. He 

 commences in this number with his visit to Paris to search 

 among the old manuscripts of the Paris Observatory for early 

 observations of occultations which had never been published. 

 We may here point out how important it is to keep a record of 

 every observation that is made, no matter whether at the time 

 it be considered useful or not. The study of what may now 

 seem apparently useless may, for all we know, in years to come, 

 become of vital importance. Such was the case with the old 

 observations of occultations made at the Paris Observatory. 

 " The astronomers had no idea of the possible usefulness and 

 value of what they were recording. So far as we can infer from 

 their work, they made the observations merely because an 

 occultation was an interesting thing to see ; and they were men 

 of sufficient scientific experience and training to have acquired 

 the excellent habit of noting the time at which a phenomenon 

 was observed." By means of these old observations " seventy- 

 five years were added, at a single step, to the period during 

 which the history of the moon's motion could be written. Pre- 

 viously this history was supposed to commence with the observ- 

 ations of Bradley, at Greenwich, about 1750; now it was 

 extended back to 1675, and with a less degree of accuracy, 

 thirty years further still." 



Referring to a meeting of the Academy of Sciences which he 

 attended four years later, he says : "In the course of the 



NO. I512, VOL. 58] 



session a rustle of attention spread over the room, as all eyes 

 were turned upon a member who was entering rather late. 

 Looking towards the door, I saw a man of sixty, a decided 

 blond, with light chestnut hair turning grey, a slender form, a 

 shaven face, rather pale and thin, but very attractive and ex- 

 tremely intelligent features. As he passed to his seat hands 

 were stretched out on all sides to greet him, and not until he 

 sat down did the bustle caused by his entrance subside. He 

 was evidently a notable. 



" Who is that?" I said to my neighbour. 



" ' Leverrier.' " 



Prof. Newcomb found Delaunay one of the most kindly and 

 most attractive of men. " His- investigation of the moon's 

 motion is one of the most extraordinary pieces of mathematical 

 work ever turned out by a single person. It fills two quarto 

 volumes, and the reader who attempts to go through any part of 

 the calculations will wonder how one man could do the work in 

 a life-time." 



, After the death of Delaunay, who was drowned when out for 

 a sail in a small boat, Leverrier was reappointed to his old 

 place at the Paris Observatory, and to him, as Prof. Newcomb 

 says, " belongs the credit of having been the real organiser of 

 the Paris Observatory. His work there was not dissimilar to 

 that of Airy at Greenwich ; but he had a much more difficult 

 task before him, and was less fitted to grapple with it." 



LORD LISTER ON EXPERIMENTAL 

 MEDICINE. 

 "T^HE address delivered by Lord Lister at Liverpool on October 

 ^ 8, on the occasion of the opening of the Thompson-Yates 

 Laboratories at the University College in that city, was briefly 

 referred to in our report of the cerer.ionj* last week. The com- 

 plete address is printed in the British Medical Journal of 

 October 15, and is reproduced below. It is a statement as to 

 the nature and value of the work to be carried on in the new 

 laboratories, and a dignified vindication of the experimental 

 method in medicine. The facts concerning experiments upon 

 animals are so often presented to the public in a distorted form, 

 that a calm exposition of the true ethical policy of vivisection, 

 such as Lord Lister gives in his address, should have a most 

 beneficial effect. 



Lord Lister's Address. 

 My Lord Chancellor, my Lord Mayor, my lords, ladies, 

 and gentlemen, — When I was honoured by the authorities of 

 the Liverpool College with the request that I would open the 

 Thompson-Yates Laboratories I little imagined that I was asked 

 to take part in so imposing a ceremonial as the present. That 

 it should have assumed such a character, that it should have 

 attracted so large and brilliant a company, including not only 

 many men from various and often distant parts of the country 

 distinguished in medicine and other branches of science, but also 

 noblemen, Church dignitaries, and persons eminent in literature 

 and in politics, seems to me a matter of great importance, full 

 of good augury for the future of the scientific practice of the 

 healing art — in other words, treatment based on real knowledge 

 as contrasted with the blind gropings of empiricism. We seem 

 to have before us to-day clear evidence that the more cultured 

 sections of the British public are becoming alive to the necessity 

 for providing adequate means for the practical study of 

 the sciences which are of the very essence of the know- 

 ledge that confers the power to recognise and treat dis- 

 ease. It an engineer is to qualify himself for detecting and 

 correcting anything wrong in a machine of human construction, 

 no verbal description or drawings will give him the requisite 

 information ; he must see and handle the details of the 

 mechanism, and watch them at work. And it might seem the 

 veriest common sense that the more practically familiar a man 

 is with the structure and working of that marvellously compli- 

 cated mechanism, the human body, the better fitted will he 

 be to deal with its disorders. Yet obvious as such a con- 

 sideration may seem, it is only in comparatively recent periods 

 that its truth has been generally recognised. I am old enough 

 to remember the years before the passing of the Anatomy Act, 

 and I recollect being told as a child of the fiendish deeds of 

 Burke and Hare, horrors which it would appear were needed to 

 arouse a prejudiced and apathetic public to the imperious 

 necessity of making it legally permissible for the intending 

 surgeon to become acquainted in the only possible way, by 



