478 Proceedings of the Royal Society of Edinburgh. [Sess. 
circumstance was his connection with Dr David Rennet, the talented and 
stimulating extra-mural teacher to whose instruction he resorted in his 
summer vacations, and to whom many years afterwards he dedicated 
his Introduction to Algebra, “in memory of happy hours spent in his 
classroom in days of old.” That he did not specialise thus early to the 
exclusion of all other intellectual pursuits may he judged from the fact 
that, when he graduated, in 1871, he received the Town’s Gold Medal, 
“awarded annually to the most distinguished scholar at the termination 
of the Arts curriculum.” By this time, however, he had found a clear 
vocation in the sphere of the mathematical sciences, as is strikingly shown 
by the fact that within less than a year he gained all the honours accessible 
to students in this department: the Simpson Prize in Mathematics, the 
Arnott Prize in Natural Philosophy, the Fullerton Scholarship in Mathe- 
matics and Physics, the Ferguson Mathematical Scholarship open to recent 
graduates from any of the four Universities of Scotland, and, finally, an 
open scholarship at Peterhouse, Cambridge. 
At Cambridge he commenced residence in 1872, and in 1875 he graduated 
as second wrangler and second Smith’s prizeman. Of his teachers during 
these three years the most influential and formative undoubtedly was 
Clerk Maxwell, who had delivered his inaugural lecture as Cavendish 
Professor of Experimental Physics in October 1871, had published his 
Treatise on Electricity and Magnetism in 1873, and had opened the 
Cavendish Laboratory in June 1874. Clerk Maxwell was not one of those 
whose instruction came within the ordinary scope of work for the Mathe- 
matical Tripos, and Chrystal, who from an early date threw himself with 
great ardour into the work of the laboratory, seems to have been regarded 
by some of his friends as having “ wasted ” a good deal of time there. But 
this was not his own opinion, nor was it borne out by the decision of the 
examiners. He found himself so well abreast of his proper tripos work 
that he had ample leisure not only for this but for other parerga, such as 
that of writing an essay on “ Wit and Humour in English Poetry,” which 
won the Members’ Prize in 1873, and also for full enjoyment of under- 
graduate companionship and the characteristic recreations of the place. 
Writing long afterwards to the late Dr Adam of Emmanuel, who was 
engaged on a memoir of that eminent scholar Mr R. A. Neil of Pembroke, 
he said : “ The happiest days of my life were my undergraduate days at 
Peterhouse, and the chief joy of that time was my friendship with Neil.” 
He rowed a little, and was for a time an energetic volunteer. Some 
sentences from his own retrospect of the three undergraduate years at 
Cambridge as compared with the four undergraduate years he passed in 
