KEY TO CLASSIFICATION 



Oil and Gas Engines. Appendix. 

 Oils and Fats, TP 670. 

 Ophthalmology, RE. 

 Ornithology, QL 671. 

 Orthopaedic Surgery, RD 701. 

 Otology, RF. 



PALEONTOLOGY, QE 701. 



Papermaking, TS 1080. 



Pathology, RB. 



Plant, SB 599. 



Petroleum, TN 870. 



Pharmacy, RS. 



Philosophical Instruments, Q 184. 



Photography, TR. 



Physical Chemistry, QD 450. 



Physics, QC 



Physiology, Animal, QP. 



Plant Pathology, SB 599. 



Postal Service. Appendix. 



Psychiatry, RC 321. 



Public Health, RA 421 and Appendix. 



RADIOACTIVITY, QC 475. 

 Radiotelegraphy, TKs 700. 

 Railway Engineering, TF. 

 Refrigeration, TP 490 and Appendix. 

 Rhinology, RF. 



SANITARY Engineering, TD. 



Science, General, Q. 



History, Q 125. 

 Scientific Instruments, Q 184. 

 Serum Therapy, RM 741. 

 Shipbuilding, VM. 



Skin Diseases, RL. 



Smoke Nuisance, RA 575. 



Soapmaking, TP 990. 



Soils, S 591. 



Sugar, TP 375. 



Surgery, RD. and Appendix. 



Orthopaedic, RD 701. 



TERRESTRIAL Magnetism, QC Sir. 



Textiles, TS 1300. 



Therapeutics, RM. 



Tropical Agriculture, SB in. 



Medicine, RC 960. 

 Tuberculosis, RC 306. 



USEFUL Arts, T. 

 VETERINARY Medicine, SF 6or. 



WINE-GROWING, TP 548. 

 Wireless Telegraphy, TK 5700. 

 Women, Diseases, RG. 



ZOOLOGY, QL. 



