296 



NATURE 



[July 29, 1897 



No. of orbits 



Eccintncitif's between 



O'O and o'l 



o-i „ 0-2 



0-2 „ 0-3 



0-3 ,. 0-4 



0-4 .. 05 



0-5 ,, 06 ... 



06 ,, 07 



07 ,, 08 



08 ,, 09 2 



0-9 ,, 10 o 



Mean average value of the eccentricity of the forty binaries, 

 0-482. 



The author thus points out that binaries are dis- 

 tinguished from the planets and satellites in two very 

 distinct respects, namely : 



(i) The orbits are highly eccentric. 



(2) The stars of a system are comparable, and fre- 

 quently almost equal in mass. 



Dr. See gives a series of illustrations of the orbits 

 arranged in the order of their eccentricity,and remarks that 

 while these are more eccentric than those of the planets 

 and satellites, they are much less eccentric than those of 

 the long-period comets. 



The reason why these orbits came to be so eccentric 

 the author evidently leaves to a second volume, as he 

 says that hereafter we shall see that the orbits were 

 originally circular. 



In Dr. See's concluding remarks, he points out that 

 these double systems stand in direct contrast to the 

 planetary systems, in which the masses of the components 

 are not in the proportion of two to one, or equal, but 

 where the central body has 746 times as much mass as 

 all of the planets combined. 



It is true that investigators, as Dr. See remarks, have 

 alvyays approached the problems of cosmogony from the 

 point of view of our solar system, and have not given 

 sufificient attention to systems of the double or triple star 

 type. This is probably owing to the fact that double star 

 astronomy is practically very modern, and that those 

 investigators were not aware that the telescope would 

 reveal such innumerable systems of double and triple 

 stars as we now know to exist in the heavens. It is 

 further natural that we should consider our system in 

 the first instance a common type of the celestial ones, 

 until it is proved on the contrary to be otherwise. Indeed, 

 such a system as ours need not be in any case an excep- 

 tional one in space ; looking at a similar one in the 

 heavens, we should most probably only be able to see 

 the central body the sun, in consequence of the smallness 

 of the components (the planets) revolving round it. 



It seems likely that such a system would be more 

 easily observed when in the nebulous stage, as, for 

 instance, in those spiral nebuL-e which have central nuclei 

 very large compared with the smaller condensations 

 scattered along the outliers. 



In conclusion, we may say that we have nothing but 

 praise for this book. By its publication double-star 

 astronomy is greatly enriched, and every double-star 

 observer and computer will find it a valuable addition to 

 his library. 



Not only will the exposition of the modern methods of 

 computation of such systems add greatly to its usefulness, 

 but a mine of valuable information regarding the previous 

 researches on the best-known members of double-star 

 systems is brought together in one volume. 



William J. S. Lockyer. 



THIERRY WILLIAM PRE YE R. 

 T^O our readers the announcement of the death of this 

 -*■ distinguished physiologist will come with surprise. 

 To those who knew Preyer it might have seemed as if 

 he, with that appearance of overflowing vigour, might 

 have looked forward to a long lease of life. It was other- 



NO 1448, VOL. 56] 



wise, for Preyer died at the comparatively early age of 

 fifty-six of Bright's disease. 



Preyer was born in Manchester in 1841, and, after 

 studying in London, he, like most German students, 

 attended several universities, including Bonn, Berlin, 

 Vienna, Heidelberg, and Paris. In 1862 he took the 

 degree of Doctor of Philosophy and that of Doctor of 

 Medicine in Bonn in 1865. In Bonn he was brought 

 under the influence of Max Schultze ; in Berlin Helm- 

 holtz, Du Bois, and Virchow inspired him with a desire 

 to become a physiologist, while later he worked under 

 Bernard in Paris. 



He commenced his independent scientific career as a 

 " privat docent " in Bonn in 1865, and shortly afterwards, 

 in 1869, .he was appointed Professor of Physiology in 

 Jena, where his best work was done. 



His energy was unbounded, his enthusiasm unquench- 

 able, and so he set to work and had erected the well- 

 known physiological institution in Jena, where he 

 remained until a few years ago, when he resigned his 

 chair, and went to Berlin, where he remained some time, 

 and then retired to live in Wiesbaden. 



Preyer's name will always remain associated with his 

 work on haemoglobin, a work inspired partly by the re- 

 searches of the Berlin School. The many-sided view 

 of his genius found its expression in the very diverse 

 subjects in which he worked and wrote. 



His well-known work "Die Seele des Kindes " (1882) 

 was a study of the mental development of his own child ; 

 it amplified and extended the less extensive observations 

 of Darwin. 



In the 'seventies his researches were chiefly acoustical, 

 and to-day there exists in the Jena Institute an extra- 

 ordinary collection of acoustical apparatus which he used 

 for his researches. 



About the same time (1877) he published his researches 

 on the cause of sleep. 



His "myophysical law "was not so well received by 

 physiologists. Many of his papers and those of his pupils 

 are published in his " Sammlung Physiologischer Ab- 

 handlungen" (1876-80), in which will be found his most 

 interesting observations on hypnotism and an allied 

 subject which he called " Kataplexie." Whatever may 

 be thought of his theory, his observations stand, and only 

 this year Verworn, of Jena, has again taken up the sub- 

 ject, and published some most interesting results of 

 " Kataplexie " in serpents. Perhaps Preyer's attention 

 was directed to hypnotism by the works of Braid, of 

 Manchester, which he translated. 



As showing the peculiar character of Preyer, and illus- 

 trating his never-ceasing quest after something new, we 

 have his physiology of the embryo, which has been trans- 

 lated into French. 



Preyer had a ready pen, he was a charming and attrac- 

 tive lecturer, and some of his popular discourses have 

 had a wide circulation. 



One of the most pleasantly written of his works is 

 his " Elements of General Physiology," in which he gives 

 a rapid, bold, and characteristic sketch of the develop- 

 ment of this subject. This work was also translated 

 into French. 



Preyer was the very personification of buoyancy and 

 good humour, and he had an open, frank expression 

 which won for him friends on every hand. He visited 

 England frequently, and those who heard him discourse 

 at the Edinburgh meeting of the British Association are 

 not likely to forget the intense impression he made on 

 his audience, not only by the extraordinary array of facts 

 with which he dealt, but also by the ease and fluency 

 with which he spoke English. Preyer had many of the 

 gifts of an orator, and when his perfervid temperament 

 was roused he carried his audience with him and brought 

 conviction to their minds by the very ardour and force 

 of discourse. 



