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XXVI. Tlie Calculus of Chemical Operations ; leing a Method for the Investigation, ly 

 means of Syinbols, of the Laws of the Distribution of Weight in Chemical Change. 

 — Part I. On tlie Construction of Chemical Symbols. By Sir B. C. Beodie, Bart., 

 F.R.S., Professor of Cliemistry in the University of Oxford. 



Received April 25,— Read May 3, 1866. 



(( 



'■ Les formules chimiques, comme nous Vavons dit, ne sont pas destinies a representer 

 V arrangement des atonies, mats elles ont pour but de rendre evidentes, de la maniere la 

 plus simple et la plus exacte, les relations qui rattachent les corps entre eux sous le rapport 

 des transformations." — Geeiiaedt. 



CONTEMTS. 



Introduction 731 



Section I. Defhsttions. — (1) Term "ponderable matter." — (2) "A chemical substance." — (3) "A 

 weight." — (4) "A single weight." — (5) "A group of weights." — (6) "Identical weights." — (7) "A 

 compound weight." — (8) A "simple weight." — (9) An "integral compound weight." — (10) " Unit 

 of ponderable matter." — (11) "Unit of space." — (12) Term "distribution of weight." — "A distri- 

 buted weight." — "An undistributed weight." 789 



Section II. On the symbols op chemical operations. — (1) Definition of "a chemical operation." — Symbols 



of chemical operations, .r, .r,, .r^. — Term "chemical function." — (2) Symbol of identit}% =. (3) 



Symbols of the operations by which groups are constituted, -)- and — . — Symbol selected as the 

 symbol of x—x.—{A) Symbol of two weights collectively considered, (a;-)- a;,). — (5) Symbols of com- 



a- 



pound weights, xy and -. — Commutative property of chemical symbols. — (6) Interpretation and pro- 

 perties of the symbol w(y +yi) 794 



Section III. On the chemical symbol 1. — (1) The symbol 1 selected as the symbol of the unit of space. 



. — (2) Various forms of the symbol 1. — Symbols a/' and -. — (3) Symbol oo 798 



x 



Section IV. Osr the pundahental chemical eotations. — (1) Equations xy=x-\-y and -=x—y. (2) 



Deduction of the forms of the symbol 1 from the fundamental equations. — (3) Consideration of tho 



equation 0= ji. — (4) Logarithmic property of chemical symbols 801 



Section V. On the symbols of simple weights. — (1) Term " prime factors." — (2, 3, 4, 5, 6, 7, 8) Pro- 

 perties of these symbols. — (9) Symbol of an integral compound weight. — (10) On the expression 



of chemical symbols by means of prime factors in a given s3-stem of equations 804 



Section VI. On the constbttction of chemical EauATioNS from the data afforded by ksperimext .... 808 



Section VII. On the symbols of the itnits of chemical substances 810 



Group 1, p. 810. — (1) Hydrogen. — Definition of the term "modulus." — (2) Oxygen. — (3) Sulphur. 

 — (4) Selenium. — (5) Chlorine. — (6) Iodine. — (7) Bromine. — (8) Nitrogen. — (9) Phosphorus. — 

 (10) Arsenic- — (11) Mercury. 

 Group 2, p. 827.— (1) Carbon.— (2) Silicon.— (3) Boron. 



Group 3, p. 839. — (1) On the relation which exists between the vapour-density and tho specific heat 

 of the elemental bodies. — (2) Symbol of Antimony. — (3) Bismuth. — (4) Tin. — (5) Zinc. — (6) 

 Cadmium. — (7) Silver. 

 Section VIII. On the apparent exceptions to the law of prime factors. — (1) Chloride of ammonium. 



— (2) Binoxidc of nitrogen. — (3) Table of exceptions 851 



Conclusion gg^ 



Even in the earliest times the attention of chemists seems to have been directed to the 

 symbolic expression of the farts of their science, a method which had its origin in the 



MDCCCLXVI. 5 



