ESSAYS 461 



II. Practical Chemistry 



The scope of practical chemistry is the study of the appearance of matter 

 and its interrelations. It is twofold — objective and subjective. 



The objective part includes not only the systematical description of 

 chemical elements and compounds, but also a study of their reactions and 

 recognition as well as the technical operations of the chemist. The old 

 and well-known classification seems practical and effective, hence : 



8. Inorganic Chemistry, or the chemistry of polar compounds generally, 

 treats of the elements and compounds not containing carbon. 



9. Organic Chemistry, or the chemistry of non-polar compounds, deals 

 mainly with the thousands of carbon compounds. 



10. Analytical Chemistry, or the chemistry of reactions, includes the 

 methods and operations as well as the apparatus and instruments for qualita- 

 tive and quantitative analysis. Its purpose is the recognition, detection, 

 and determination of the composition of matter — in short, the main part 

 of professional chemistry. 



The subjective part of practical chemistry describes the material structure 

 of the universe, that is, the chemical composition and changes in nature. 

 Accordingly, it is divided into : 



11. AsTROCHEMisTRY, which explores the chemical structure of the 

 cosmos, and, with the help of photochemical methods, discovers the con- 

 stituents of celestial bodies. It glimpses into the great cycle of world- 

 creation and world-disaster — a transformation requiring eons — and hints 

 at a cosmical evolution from latent nebulae into radiant suns and their 

 gradual decline. 



12. Geochemistry, which investigates the composition of our planet 

 and teaches the changes occurring in the atmosphere, hydrosphere, and 

 Uthosphere. Air, oceans, and rocks are its kingdom, and it studies their 

 transformation, decay, and formation, as well as the great cycle of water, 

 the pulsating carrier, diffuser, and concentrater of matter. 



13. Biochemistry, which investigates the chemical secrets of life and 

 inquires into the functions and actions (physiological), as well as the structure 

 (morphological) of cells in their healthy or diseased (pathological) condition. 

 The chemical dynamics of life phenomena considers not only the protoplasm 

 and cell community of plant, animal, or man as a chemical mechanism 

 (metabolism), but also its material relation to the surrounding nature, e.g. 

 the carbon cycle, nitrogen cycle, phosphorus cycle, etc. 



III. Applied Chemistry 



The ultimate purpose of all science is the progress of mankind, be it 

 either for material or spiritual improvement. Hence, the more or less 

 apparent purpose of applied chemistry is to serve the welfare of man. This 

 application, of course, is either IIIa— direct, or IIIb — indirect. 



The direct application of chemistry can be grouped under : 



14. Sanitary Chemistry, including the supervision of water-supply, 

 sewage, sanitation, waste disposal, and other hygienic necessities. 



15. Pharmaceutical Chemistry, dealing with the composition, manu- 

 facturing, and testing of remedies, while Therapeutical Chemistry studies 

 the application, dosage, and effect of remedies. 



16. Medical Chemistry, or clinical chemistry, employs analytical 

 methods for diagnostic purposes, whether it be for the detection of disease 

 or crime. 



17. Food Chemistry, or chemistry of nutrition, examines and controls 

 the production and preparation of food products, and includes the methods 

 of detecting adulterants and preservation. 



