=500 Natural Science.=
501 Philosophy.
502 Compends.
503 Dictionaries.
504 Essays.
505 Periodicals.
506 Societies.
507 Education.
508 Travels.
509 History.
=5l0 Mathematics.=
511 Arithmetic.
512 Algebra.
513 Geometry.
514 Trigonometry.
515 Conic sections.
516 Analytical geometry.
517 Calculus.
518 Quaternions.
519 Probabilities.
=520 Astronomy.=
521 Theoretical.
522 Practical.
523 Descriptive.
524 Maps.
525 Observations.
526 Figure of the earth.
527 Navigation.
528 Almanacs.
529 Chronology.
=530 Physics.=
531 Mechanics.
532 Hydrostatics.
533 Pneumatics.
534 Acoustics.
535 Optics.
536 Heat.
537 Electricity.
538 Magnetism.
539 Molecular physics.
=540 Chemistry.=
541 Theoretical.
542 Experimental.
543 Analysis.
544 _Qualitative._
545 _Quantitative._
546 Inorganic.
547 Organic.
548 Crystallography.
549 Mineralogy.
=550 Geology.=
551 Physical Geography, Meteorology.
552 Lithology.
553 Dynamical geology.
554 Europe.
555 Asia.
556 Africa.
557 North America.
558 South America.
559 Oceanica.
=560 Paleontology.=
561 Plants.
562 Invertebrates.
563 _Protozoa and Radiates._
564 _Mollusca._
565 _Articulates._
566 Vertebrates.
567 _Fishes._
568 _Reptiles and Birds._
569 _Mammals._
=570 Biology.=
571 Prehistoric Archæology.
572 Ethnology.
573 Natural History of Man.
574 Homologies.
575 Evolution.
576 Embryology.
577 Spontaneous generation.
578 Microscopy.
579 Collectors' Manuals.
=580 Botany.=
581 Physiological.
582 Systematic.
583 Ornamental.
584 Europe.
585 Asia.
586 Africa.
587 North America.
588 South America.
589 Oceanica.
=590 Zoology.=
591 Comparative Anatomy.
592 Invertebrates.
593 _Protozoa and Radiates._
594 _Mollusca._
595 _Articulates._
596 Vertebrates.
597 _Fishes._
598 _Reptiles and Birds._
599 _Mammals._