MODERN CHEMISTRY. 455 



And while coal thus ministers even to the most delicate 

 works of art, a fetid oil (Fusel Oil), obtained during the 

 distillation of spirits, is made by the refinements of chemical 

 process to afford all the delicate odours of the most fra- 

 grant fruits. These transformations are the achievement 

 of the Organic Chemistry of our day. 



In the system of classification by homologous series we owe 

 much to the various labours of Grerhardt, and to those which 

 Hofmann is ever so successfully prosecuting. The question 

 as to the nomenclature best adapted to express these series, 

 is still beset with various difficulties. The present scheme 

 (mainly founded on the views of Berzelius and Grerhardt), 

 though well fulfilling all important practical objects, may 

 probably be considered provisional only. In the case of 

 Chemistry very especially, nomenclature becomes almost a 

 science in itself; such and so complex are the objects it is 

 called upon to denote. 



A wonderful part of the phenomena of Organic Chemistry 

 is the diversity of properties produced, even by slight changes 

 in elementary composition and proportions. We have already 

 noted this in certain instances ; but the proofs, most singular 

 and impressive, are those connected with the influence of 

 organic agents on animal life. An atom added to or ab- 

 stracted from a compound, determines whether the product 

 be wholesome or noxious an aliment or a poison. So closely 

 is the Chemistry of the material world around us associated 

 with that still more refined and mysterious Chemistry, which 

 ministers to the phenomena of life I Every solid tissue, every 

 fluid of the body, has its appropriate chemical composition 

 and relations. Every organic function either depends upon 

 or involves chemical changes in its progress* The air we 

 breathe is no sooner within the lungs than these changes 

 begin ; analogous to combustion in their nature, and effecting 

 that transformation from venous to arterial blood, which is 



