9 D 



Division 6500 shall include all entries relating" to tlie analysis 

 of composite materials such as drugs, foods, soils, waters and 

 technical products g-enerally, arranged under appropriate 

 significant headings. (For analysis of minerals and rocks see also 

 -G 32, 87). 



Theoretical and Physical Chemistry. 



7000 General. 



7050 Conditions and laws of chemical change. 



7100 Mass properties. 



7150 Mechanical properties. 



7200 Thermal properties. 



7250 Electrical and magnetic properties. 



7300 Optical properties. 



7350 Photo-chemistry. 



The entries in these sections shall be arranged under appro- 

 priate significant headings. 



Section 7000 shall include general speculations on energetics, 

 entropy, philosophy, and the theory of cognition, as well as all 

 entries of a general character relating to such subjects as the 

 ■constitution of matter, the molecular and atomic hypothesis, the 

 •classification of elements and of compounds, the periodic law^ 

 .&c., allotropj'' (to include all forms of isomerism, see also G 500- 

 540) and structure, interrelationship of gases, liquids and solids, 

 .&c. {See also C Physics). 



Section 7100 shall include all entries relating to atomic and 

 molecular weights, to densities of gases, liquids or solids (sec 

 a/50 B 0140; G 18o0j, to molecular and atomic volumes, and to 

 cr^'stallography. 



Section 7150 shall include all entries relating to motion, 

 diffusion, solubility, cohesion, surface tension {see also C 0300), 

 and viscosity. {See also B 2540, 3650). 



Section 7200 shall include all entries relating to combusti(jn 

 and flame, di?-sociation, therrno-chemistry, melting and boiling 

 points {see also C 1<S10, 1840), specific and latent hearts {see (tlso 

 •C 1620, 1640, 182U), electric furnace operations. 



Section 7250 shall include all entries relating to electrolysis 

 which do not come uader analysis. {See also C 6200-6250, and 

 (magnetic) C 6650). 



Physiological Chemistry. 



8000 General. {See also Q 1010-1085). 

 8010 Enzymes. (&'e a/.«o Q 1200-1240, 8335, 91 60y 

 8020 Fermentation. {See also L 5000 ; M 3100 ; R 1820). 

 8030 Vegetable metal)()lism. 

 8040 Animal metabolism. {See also Q 7900). 

 8050 Pathologic changes — immunity. 

 The entries under these headings shall be confined to notices 

 •of specifically chemical work on the subjects scheduled. 



