284 Royal Irish Academy. 



whicli made him so distinguished in after-life. He entered 

 Trinity College, Dublin, in 1838, and after a very successful under, 

 graduate career, he was, in 1844, elected Fellow thereof, at the early 

 age of 23, and on his first appearance as a candidate for the office. 

 Having attained this position chiefly by mathematics and mathematical 

 physics, he allowed his early interest in Natural History to reassert 

 itself ; and when, by the appointment of Professor Oldham to the 

 Directorship of the Geological Survey of India, in 1851, the Chair of 

 Geology in the University became vacant, Dr. Haughton was elected 

 thereto as the most suitable person for the post. During the thirty 

 years of his occupation of it, besides the instruction of his classes, he 

 did a large amount of original work in Geology, in the form of nume- 

 rous Papers which have appeared in the publications of the Eoyal 

 Society of London, the Eoyal Irish Academy, and the Journals of the 

 Geological Societies of London and of Ireland, &c. The composition 

 of the granites of Ireland and of Scotland especially engaged his 

 attention. He wrote also on various palseontological and minera- 

 logical subjects. 



His knowledge of mathematics and physics enabled him to attack 

 sundry questions in Physiology and in Cosmology, some of which 

 latter are still under discussion. We may here note his "Manual of 

 Geology" (first edition, London, 1865), and his " Lectures on 

 Physical Geography " (in the Dublin University Press series) ; 

 both books being marked with his usual originality and versatility. 



His studies in Palaeontology suggested to him to take up the sub- 

 ject of human anatomy and physiology, and for this purpose he 

 entered the Medical School and followed out its course as a young 

 student might do, and took the degree of M.D. in 1862. He after- 

 wards wrote various Papers in medical and other publications on 

 physiological and pathological subjects. One result of his anatomical 

 studies was his book on the "Principles of Animal Mechanics" 

 (London, 1873). This work occupied his attention for a long time ; 

 it consisted principally of many Papers written on the subject during 

 a period of ten years. This undertaking was of special interest to 

 him ; as it opened to him a new line of discovery by the application of 

 mathematics to the structure and mode of working of the muscular 

 system of the vertebrate animals. He obtained, in many cases, illus- 

 trations of the Principle of Least Action in the vertebrate organization. 



