360 M. F. Zollner on a New Spectroscope, together with 



the healthy, whilst for those affected with scurvy it is absolute 

 poison. In order to keep off the latter disease, a certain and 

 not too small quantity of lemon-juice and sugar must be taken 

 daily, besides vegetables, the eating of which in abundance is of 

 great benefit. Nowadays, when all these things can be so easily 

 procured of good quality, there is not the least difficulty in pro- 

 visioning a ship in the most suitable manner. 



The third thing upon which the vigour and welfare of a win- 

 tering company depend is warm clothing, which should consist 

 less of furs than of several layers of woollen stuffs one over the 

 other. 



XLII. On a New Spectroscope, together with contributions to the 

 Spectral Analysis of the Stars. By F. Zollner*. 



IN recent tiaies the spectrum-analysis of the stars, apart from 

 its disclosures as to the physical constitution of the celestial 

 bodies, has begun to claim attention in another and not less 

 interesting direction; for it affords a prospect of demonstrating 

 and, under favourable circumstances, even of measuring the in- 

 fluence which the component of the relative motion of the earth 

 and of the star observed, acting along the line joining them, 

 exerts upon the position of the lines of the spectrum in question. 



A simple consideration shows that actions which two separated 

 bodies exert upon one another through periodical impulses of 

 finite velocity of propagation, must be modified by a steady alte- 

 ration in the distance of the two bodies. To Doppler, in the year 

 1841 f, is due the merit of having first recognized this influence, 

 though the conclusions which he deduced therefrom as to the 

 colour of the stars must be admitted to be incorrect, owing to his 

 having neglected the invisible part of the spectrum. 



The experiments of Ballot, Mach, and others have shown that, 

 as regards sound, the influence in question is in accordance with 

 the requirements of the theory. 



In the case of light, it has not hitherto been possible to con- 

 firm by observations magnitudes of that influence which could 

 with certainty be demonstrated ; for even the cosmical motions, 

 which are the greatest we can use for this purpose, are very 

 small when compared with the velocity of the propagation of light. 



Yet the great improvements which, since the discovery of 



* Translated from Poggendorff's Annalen, September 1869, having been 

 read before the Royal Saxon Society of Sciences, February 6, 1869. 



t " Ueber das farbige Licht der Doppelsterne und einiger anderer 

 Gestirne des Himmels," Abhandlungen der Bohm. Ges. d. W. vol. ii. 

 (1.841-42) pp. 465-482. 



