On the Brightness of the Corona of April 16, 1893. 403 



visceral and cutaneous, seems to me as to others hardly over-estimable 

 for the study of the subject. Wundt,* A. Mosso,t Alf. Lehmann,| 

 Head,§ and Wright] ] are among those who have in recent years laid 

 stress on that aspect of the phenomenon. I would not be thought to 

 impugn the importance of the study of such organic phenomena in 

 connection with emotional mental states. The only respect in which 

 the here given observations affect the position of affairs is, that they, 

 I think, render it necessary to attribute to these elements of emotion 

 another significance than that imputed by the authorities quoted in 

 my opening paragraph. The picturesque incisiveness of all that 

 comes from Professor James's pen, renders the more persuasive any 

 argument that it pursues. His suggestive chapters led to the above 

 attempt at examination of his theory, an examination the incom- 

 pleteness of which I wish to unreservedly acknowledge. 



The expenses of this investigation have been in part met by a grant 

 given by the Eesearch Committee of the British Medical Association. 

 I would take this opportunity of tendering to them my best thanks for 

 their generous support. 



On the Brightness of the Corona of April 16, 1893. Preliminary 

 Note." By H. H. Tuenee, M.A., F.E.S, Savilian Professor. 

 Eeceived March 29,— Eead May 10, 1900. 



The visual brightness of the corona was measured at the total 

 eclipses of August 29, 1886, and April 16, 1893, by Professor T. E. 

 Thorpe, using a method arranged by Sir W. Abney ('Phil. Trans.,' 

 A, 1889, p. 363, and 1896, p. 433). Soon after the first of these 

 •eclipses, Sir W. Abney devised a method of measuring the brightness 

 photographically, by exposing a portion of the plate, which was not 

 ■exposed to the sky, to a standard light passed through a row of small 

 square screens of varying and known thickness. The result is a 

 series of " standard squares " on the plate, which show the density of 

 deposit due to standard lights of known values ; and by comparing 

 the density of the coronal image we find the brightness of the corona 

 in terms of these standard lights. 



These squares were first put on the coronal photographs by English 

 observers at the eclipse of December, 1889, and have been syste- 

 matically used by them since. The 1889 photographs have not yet 

 "been measured. Some measures of the 1893 photographs were made 

 iby me in Sir W. Abney's laboratory at South Kensington, in July, 



* * G-rundriss d. Psychologie,' vol. 1, 3te Auflage, Leipzig, 1893. 



t ' La Paura,' Milano, 1885. 



X * Das aefiihlsleben,' Leipzig, 1892. 



•§ "Visceral and referred Pains," Parts I, II, and III, Brain, 1893-7, London, 

 fil Ihid., " The Physiological Element in Emotion," 1894, London. 



