The relative commercial value of the articles sold as coal tar creosote and wood creosote disposes of the question as to the latter being present in the former article, and we are quite certain that the cheap variety is nothing more or less than a phenol or carbolic acid. Wood creosote, it has been frequently stated, is adulterated with coal tar creosote, or phenol. The object of my experiments has been to prove the identity of wood creosote and its freedom from phenol. The following tests are laid down in various works as conclusive evidence of its purity, and each has been fully tried with the several samples of wood creosote to prove their identity and purity, and also with phenol, sold as commercial creosote or coal tar creosote, and for comparison with mixtures of the two, that even small percentages of admixture might be identified, should such exist in the wood creosote of the market. The following tests were used: 1. Equal volumes of anhydrous glycerine and wood creosote make a turbid mixture, separating on standing. _Phenol dissolves_. If three volumes of water be added, the separation of the wood creosote is immediate. _Phenol remains in permanent solution_. 2. One volume of wood creosote added to two volumes of glycerine; the former is not dissolved, but separates on standing. _Phenol dissolves_. 3. Three parts of a mixture containing 75 per cent, of glycerine and 25 of water to 1 part of wood creosote show no increase of volume of glycerine, and wood creosote separates. _Phenol dissolves, and forms a clear mixture_. Were any phenol present in the wood creosote, the increase in the volume of the glycerine solution, if in a graduated tube, would distinctly indicate the percentage of phenol present. 4. Solubility in benzine. Wood creosote entirely soluble. _Phenol is insoluble_. 5. A 1 per cent, solution of wood creosote. Take of this 10 cubic centimeters, add 1 drop of a test solution of ferric chloride; an evanescent blue color is formed, passing quickly into a red color. _Phenol gives a permanent blue color_. 6. Collodion or albumen with an equal bulk of wood creosote makes a perfect mixture without coagulation. _Phenol at once coagulates into a more or less firm mass or clot_. 7. Bromine solution with wood creosote gives a reddish brown precipitate. _Phenol gives a white precipitate_. All tests enumerated above were repeatedly tried with four samples of wood creosote sold as such; one a sample of Morson's, one of Merck's, one evidently of German origin, but bearing the label and capsule of an American manufacturer, and one of unknown origin, but sold as beech-wood creosote (German), and each proved to be _pure wood creosote_. Two samples of commercial creosote which, from the low cost, were known to be of coal tar origin gave the negative tests, showing that they were phenol.