378 !'• 1^*- IIMIN. 



Se])teniber. J 875. found Ur. Jlahn back in Suiitli Africa, and 

 within four months of his return he had assumed the chair of 

 chemistry at the South African Colleg^e ; his ap])'iintment was, in 

 fact, made on his 27th l)irthday. Hahn's assumj^tion of that 

 chair, hke his regretted xacation thereof through death, was 

 ahnost coincident with a radical change in the echicational system 

 olf Soutli Africa: the University of the Cajje of ( iood Hope had 

 just received its charter, and had replaced the old Board of 

 Examiners ; Prof. Roderick Noljle, Professor of Chemistry at the 

 South African College, had beeii elected by the newly-formed 

 convocatioi) as a member of the University Cotnicil. l)ut had died 

 after a little more than a year's tenure of the latter ofhce. and so 

 it came about that I^rof. Hahn. a few months after his return to 

 South ;\frica, was elected a meiubcr of the first Council of 

 tiie Cape of Good Hope University. On each subsequent occa- 

 sion he had 'been re-elected, and had therefore at the time of his 

 death held his seat on the Uni\ersity Council continuously for 42 

 years. His occupancy of the chair of chemistry at the South 

 Aifrican College has thus spanned practically the entire period 

 of existence of the Cape of Good Hope University, from near 

 the start to the finish. For zy years Prof. Hahn remained the 

 sole direct representative of chemical science on the Coiuicil of tb.e 

 University, until he was joined, in 1903, by Mr. J. Martin, at 

 that time Professor of Chemistry at the Diocesan College, 

 Rondebosch. 



P'of. Hah'i began his work in connection with the Soiuli 

 African College in a tiny room called a laboratory by barest 

 courtesy, and from the very start his lectures were characterised 

 by three outstanding qualities, systeiuatic arrangeiuent of subject, 

 lucidity of explanation, painstaking attention to detail. In atldi- 

 tion. he ever evinced the utmost patience with any student who 

 failed to grasp some point in either a \erl)a] exi)osition or a 

 practical experiment, and never shrank from a step-by-ste]> 

 repetition of any obscure phase in a lectin-e, or of some involved 

 calculation. These were the qualities that made Hahn's lectures 

 so attractive and successful. A former student of his. who 

 afterwards " sat under " the late Sir William Ramsay, the 

 eminent discoverer of argon and the other inert gases in the 

 atmosphere, said that although Ramsay excelled as a manipula- 

 tor in exj^eriments of extreme delicacy, he could not touch Hahn 

 as a lecturer. The latter's gift of infusing a charm into his 

 subject was rarely equalled, even when his audience consisted 

 of boys three years below matriculation stage, to whom the 

 educational system of the seventies and eighties compelled him 

 to lecture. fJe possessed a special knack of imparting to students 

 exactly the mental ]jal)ulum suited to their particular capacit\-. 

 Once when he found an enthusiastic young student endeavouring 

 to supplement the notes of his lectures by studying a treatise in 

 advance of his years, Hahn told tiie boy that "milk from two 

 cows at the same time is not good for a child." 



Hahn had not occupied his chair many years ere his person- 



