23*] 
TOXIC ACTION AND CHEMICAL COMPOSITION. 
29 
Potassic Oxalate ........ 0 
Amylene Hydrate ........ 6 
Spirits of Camphor.7 
Iodine.7 
Alcohol .......... 8 
Caustic Soda ......... 8 
Nicotine .......... 8 
Aconite .......... 10 
Acetic Acid . . . . . . . . .12 
Chloroform ......... 16 
Chloral .......... 17 
Nitric Acid ......... 19 
Sulphuric Acid......... 24 
Phosphorus ......... 26 
Arsenic .......... 37 
Mercury .......... 56 
Belladonna ......... 64 
Strychnine ......... 80 
Veronal . . . . . . . . . .119 
Prussic Acid ......... 126 
Ammonia.......... 140 
Potassic Cyanide ........ 142 
Hydrochloric Acid . . . . •. . . .313 
Opiates .......... 338 
Carbolic Acid ......... 363 
Oxalic Acid ......... 448 
Ptomaines, Food-poisoning ...... 477 
IV.—The Connection between Toxic Action and Chemical 
Composition. 
§ 23. Considerable advance has been made of late years in the study 
of the connection which exists between the chemical structure of the 
molecule of organic substances and physiological effect. The results 
obtained, though important, are as yet too fragmentary to justify any 
great generalisation ; the problem is a complicated one, and as Lauder 
Brunton justly observes :— 
“ The physiological action of a drug does not depend entirely 011 its 
chemical composition, nor yet on its chemical structure, so far as that 
can be indicated even by graphic formula, but upon conditions of solu¬ 
bility, instability, and molecular relations, which we may hope to discover 
in the future, but with which we are as yet imperfectly acquainted.” 1 
The occurrence of hydroxyl, whether the substance belong to the 
simpler chain carbon series or to the aromatic carbon compounds, appears 
to usually endow the substance with more or less active and frequently 
poisonous properties, as, for example, in the alcohols, and as in liydro- 
xylamine. It is also found that among the aromatic bodies the toxic 
action is likely to increase with the number of hydroxyls : thus phenol 
has one hydroxyl, resorcin two, and phloroglucin three ; and the toxic 
1 Introduction to Modern Therapeutics (Lond. 1892), p. 136. 
