OP ARTS AND SCIENCES. 519 



observation, and therefore a disciplinary study of the highest value." 

 Accordingly a certain amount of mineralogy was crowded iuto the 

 single chemical elective, and when, in 1868, a second elective was 

 introduced, this was devoted entirely to that subject, leaving all the 

 time of the original course for qualitative analysis. 



After this time there was a continual increase in the number of the 

 chemical courses, until, in 1871, the single laboratory of the original 

 building became overcrowded, and new accommodations were secured 

 by adding to Boylston Hall a story, which contained a large laboratory 

 for elementary students. At about the same time the chemical de- 

 partment of the, Lawrence Scientific School was merged in that of the 

 College, and all the chemical material was removed from the Scientific 

 School building to Boylston Hall. Cooke had now essentially accom- 

 plished the three tasks which confronted him when appointed Erving 

 Professor. Chemical teaching was established in the College ; the new 

 methods of instruction had been introduced ; and equal rights for 

 science had been gained after a hard struggle in the Faculty, in which 

 Cooke took a prominent part, and showed rare powers as a debater 

 and a strategist. It only remained for him to gather the fruits of the 

 victory. 



In 1872 he was elected a member of the National Academy of 

 Sciences. In 1873 he was made Corresponding Secretary of our 

 Academy, and for twenty years after this he managed our corre- 

 spondence and publications, and to him is due the establishment of an 

 annual volume of the Proceedinsfs. 



Of the many courses of popular lectures which he gave at this 

 time, one delivered before the Lowell Institute of Boston was em- 

 bodied in a book called " The New Chemistry " (1874), containing a 

 clear popular account of the modern chemical theories, which he had 

 already treated in a more technical way in his Chemical Philosophy. 

 This book had a striking success. It ran through five editions in 

 English in four years, and was translated into nearly all the civilized 

 languages of the globe. It still remains one of the best and most 

 readable statements of the theories of chemistry. 



In 1876 he Avas elected an Honorary Member of the London 

 Chemical Society, and a few years later a Member of the Royal 

 Institution. 



One of his principal amusements was photography, in which he 

 attained remarkable skill, and not only did he take excellent photo- 

 graphs himself, but he collected an enormous number of photographic 

 slides, and his frequent exhibitions of these to his friends or his classes 



