169 



ml Stwu. 



PROGRESS OF CHEMISTRY. 



LORD Wrottesley, in his Presidential Address to the British 

 Association, at Oxford, thus took a survey of the recent progress of 

 Chemical Science : — 



" In Chemistry I am informed that great activity has been dis- 

 played, especially in the organic department of the science. For 

 several years past processes of substitution (or displacement of one 

 element or organic group by another element or group more or less 

 analogous) have been the main agents employed in investigation, and 

 the results to which they have led have been truly wonderful ; 

 enabling the chemist to group together several compounds of com- 

 paratively simple constitution into others much more complex, and 

 thus to imitate, up to a certain point, the phenomena which take 

 place within the growing plant or animal. It is not indeed to be 

 anticipated that the chemist should ever be able to produce by the 

 operations of the laboratory the arrangement of the elements in the 

 forms of the vegetable ceil or the animal fibre ; but he may hope to 

 succeed in preparing some of the complex results of secretion or of 

 chemical changes produced within the living organism, — changes 

 which furnish definite crystallizable compounds, such as theformiates 

 and the acetates, and which he has actually obtained by operations 

 independent of the plant or the animal. 



"Hofmann, in pursuing the chemical investigation of the remark- 

 able compound which he has termed Triethylphosphine, has obtained 

 some very singular compound ammonias. Triethylphosphine is a 

 body which takes fire spontaneously when its vapour is mixed with 

 oxygen, at a temperature a little above that of the body. It may be 

 regarded as ammonia in which an atom of phosphorus has taken the 

 place of nitrogen, and in which the place of each of the three atoms 

 of hydrogen in ammonia is supplied by ethyl, the peculiar hydro- 

 carbon of ordinary alcohol. From this singular base Hofmann has 

 succeeded in procuring other coupled bases, which though they do 

 not correspond to any of the natural alkalies of the vegetable king- 

 dom, such as morphia, quinia, or strychnia, yet throw some light 

 upon the mode in which complex bodies more or less resembling them 

 have been formed. 



"The power which nitrogen possesses of forming a connecting 

 link between the groups of substances of comparatively simple con- 

 stitution, has been remarkably exemplified by the discovery of a 

 new class of amide acids by Griess, in which lie has pointed out a 

 new method, which admits of very general application, of producing 

 complex bodies related to the group of acids, in some measure 

 analogous to the Poly-ammonias of Hofmann. 



"Turning to the practical applications of chemistry, we may refer 

 to the beautiful dyes now extracted from aniline, an organic base 

 formerly obtained as a chemical curiosity from the products of the 



