426 Scientific Intelligence. 



outfit catalogued on pp. 428-431, may without other aid, make 

 them an intimate part of his personal knowledge. On this surest 

 foundation the demonstrated laws and current hypotheses of the 

 science are skilfully constructed and displayed, 



The short Introduction of three pages in four paragraphs with 

 a single experiment defines the province of chemistry, Chapter I 

 in 5 pages, 11 paragraphs and two experiments, sets forth the 

 material and complex nature of common air and shows the mak- 

 ing of oxygen from " mercury rust." Chap. II of 4 pp. in 5 1~T 

 with 2 exp's. develops the properties of oxygen in some detail. 

 In Chap. Ill of 3 pp. 3 ^[^[ and 1 exp. the isolation of nitrogen is 

 exhibited, its physical and chemical properties and its occurrence 

 in nature are stated and the laws of Charles and Boyle are very 

 clearly enounced. Chap. IV of 13 pp. 19 %^ and 10 exps. gives 

 an admirable exposition of the chemistry and chemical physics of 

 water. The caloric and thermal unit, the laws of definite propor- 

 tions by weight and volume, molecules, atomic weights, the dis- 

 tinction between elements and compounds, distillation, solution, 

 supersaturation and water of crystallization are very suitably 

 developed, described or demonstrated. Chap. V, 12 pp., 13 ^[^[, 

 6 exps. treats of hydrogen and its dioxide with explanation of 

 reactions, substitution or replacements, molecular weights, crith, 

 vapor density, gas-diffusion and heat of formation are here ex- 

 plained. 



Compounds of Nitrogen ; Hydrochloric Acid ; The Halogens ; 

 Ozone; Sulphur, Selenium and Tellurium, are the subjects of 

 Chapters VI to X. In them are considered incidentally Multiple 

 Proportions, by weight and volume ; Acids, Bases and Salts ; 

 Distinction of Metals from Non-metals; Nascent State; Valence 

 and Replacing Power; Chemical Calculations ; Allotropism ; Crys- 

 tal Systems ; Dimorphism ; Dissociation. 



Chapter XI of 8 pp. is purely doctrinal and is paragraphed as 

 follows: Combination by Volume; Molecular Condition of Ele- 

 mentary Gases ; Volumetric Interpretation of Symbols ; Varia- 

 tion in the HS3 umber of Atoms in the Molecule of the Same Element ; 

 Atomic Weight and Specific Heat. The law of Avogadro and 

 that of Dulong and Petit are here set forth. 



Chapter XII of 8 pp. and 8 1~^[ is devoted to Formulas, Em- 

 pirical and Rational ; their Determination ; a brief account of 

 Dualistic and Typical formulas, and a fuller statement of the 

 character and uses of Structural or Graphic Formulas. 



The next three chapters are occupied respectively with Phos- 

 phorus, with Arsenic, Antimony and Bismuth and Silicon and 

 Boron. Four chapters, aggregating 128 pp. are devoted to Car- 

 bon and its Compounds. In Chap. XVI the properties of 

 Carbon and of its oxides and sulphides, and the subjects of Com- 

 bustion and Illumination are fully discussed while decay, putre- 

 faction, fermentation, compound radicals, the blowpipe, and 

 kindling temperatures, are more briefly noticed. Chapters XVII, 

 XVIII and XIX are an excellent epitome of organic chemistry. 



