PRESIDENTIAL ADDRESS, 515 



determination of the constitution of the colouring matters of a number of plants 

 ■which are employed as dyes in India and the Colonies. Professor A. H. Church, 

 F.R.S., has determined the composition of many new or little known food grains. 

 Dr. Crossley, Dr. Le Sueur, and Dr. Lewkowitsch have examined the constituents 

 of a large number of fats and oils furnished by seeds of Indian and African origin. 

 Dr. W. J. Russell, F.R.S., has been furnished with selected materials for examina- 

 tion in connection with his interesting investigations of those substances which 

 affect the photographic plate in the dark, whilst the Hon. R. J. Strutt, F.R.S., 

 has investigated the radioactivity of a number of new or little known minerals 

 containing rare earths. Last year over 500 different materials and problems were 

 submitted from the Colonies and India for investigation to the Scientitic Depart- 

 ment of the Imperial Institute, and each year there must remain an increasing 

 number of interesting subjects which cannot be included in the Department's annual 

 programme of work. Many of these would furnish excellent subjects for chemical 

 research by advanced students in connection with the universities and technical 

 colleges throughout the country. It is nearly always possible to arrange to 

 furnish the necessary material for any competent worker to deal with. Next year 

 .a list of such subjects awaiting investigation v/ill be available at the Imperial 

 Institute for those in search of subjects for chemical research. 



Whilst the investigation of some of these subjects may at once produce results 

 of scientific value, many of them present difficulties in their investigation which 

 are far more serious than those which attend the iisual synthetical work in 

 organic chemistry. I do not know of any more profitable experience for the 

 advanced student who is already familiar with the principles of organic chemistry 

 and of laboratory practice than the separation in the pure state of the chemical 

 constituents of a plant and the determination of their chemical constitution. In 

 inorganic chemistry the examination of a new mineral furnishes similar experience. 



In carrying out research of the kind I am advocating, the chemical investigator 

 will have the additional advantage of knowing that the scientific results he obtains 

 will contribute to the knowledge of the resources of the British Empire, and 

 possibly be the means of laying the foundations of new industries. 



I need hardly remind chemists that some of the most important discoveries in 

 our science, and many of those which have had the most profound influence on the 

 development of chemical theory, have arisen from the examination of the con- 

 stituents of raw materials. The discovery of morphia in opium led to the recog- 

 nition of the new class of alkaloids ; the discovery of amygdalin in the bitter 

 almond of the new group of glucosides ; the investigation by Liebig and Wdhler 

 of the chemical properties and composition of the essential oil of the bitter almond 

 was largely instrumental in laying the foundations of modern organic chemistry ; 

 whilst it was during the examination of the constituents of bran that Fownes was 

 led to the discovery of furfurol and the subsequent recognition of a new type of 

 organic compound. In more recent times the examination of the constituents of oil 

 of turpentine and various essential oils yielded by different plants has been the 

 means of elucidating the chemical theory of the great group of terpeces, and latterly 

 Harries' investigation of caoutchouc has led to the discovery of the ozonides 

 which seem likely to be of much importance as a new means of determining the 

 constitution of certain classes of organic compounds. Lastly, I may remind you 

 that the discovery of helium might have been long delayed had not Professor 

 Miers drawn Sir William Ramsay's attention to the so-called nitrogen furnished 

 by the mineral cleveite. 



I have thought that it would be of interest on the present occasion if some 

 account were given in the Section of the chemistry of certain of the raw materials 

 employed in the principal manufacturing industries of the city of York. These 

 industries are vitally concerned with an adequate supply of certain raw products 

 of tropical origin, especially cocoa and gums. In connection with the first of these, 

 which has hitherto been obtained chiefly from the West Indies, a new industry of 

 cocoa production has sprung up in West Africa, notably in the Gold Coast and in 

 Lagos. This West African cocoa presents some peculiarities which have rendered 

 it desirable to examine the nature of its constituents. Gums of the nature of 



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