A small amount of the Barium acids was sealed with concentrated nitric acid in a hard glass tube and heated in a bomb furnace for an hour and a half at 115 to 120 degrees Centigrade. On cooling a yellow solid separated. Qualitative tests showed that this oxidation product contained no nitrogen, combined with sodium hydroxide readily, is soluble in hot water, slightly soluble in cold water, easily soluble in ether, alcohol and benzol and slightly soluble in carbon tetrachloride. It decolorizes alkaline permanganate but does not decolorize bromine water.

That there are a number of intermediate products formed and that nitration also takes place during the formation of these intermediate products is shown by the following. A small quantity of the acids were placed in a test tube and covered with concentrated nitric acid. This was suspended in an H2SO4 bath and a thermometer inserted so as to observe the temperature. On being gently warmed the nitric acid and the resin began to react with a rapid evolution of carbon dioxide and oxides of nitrogen. As soon as the reaction had modified and before the temperature rose above one hundred degrees Centigrade, a small amount was removed and added to water. Some of the solid acid was formed and also a number of globules of oil and there was a strong persistent odor of nitrobenzene. The original test tube was heated to about one hundred and twenty degrees centigrade and a small portion again removed. There was more of the solid material formed and the odor was similar to vanillin or coumarin or cinnamic aldehyde. The test tube was again tested when the temperature had reached one hundred and thirty five degrees Centigrade. There was no aromatic odor and a large amount of the solid formed. When viewed under the microscope the substance had the appearance of curled threads.

When the barium acids were treated with the standard nitrating mixture, a solid was obtained which showed the presence of nitrogen when the standard test was applied.

After the preliminary tests were made, the following method of preparation was used. Two or three grams of the barium acids were introduced into a hard glass tube of about thirty centimeters in length and fifteen or twenty cubic centimeters of concentrated nitric acid added. The reaction which is very vigorous at first was regulated by keeping the tube under running water. After this vigorous action was over the tube was placed in a sulphuric acid bath, and the temperature gradually increased until it had reached one hundred and twenty five degrees Centigrade, at which temperature it was kept for about five hours. It was necessary to add a small quantities of nitric acid from time to time to make up the loss by evaporation. When the oxidation was completed the product was poured into water and then heated to boiling. The resulting solution was filtered and the filtrate allowed to cool. On standing a quantity of a pale yellow substance separated. The following data gives the percent yield of this oxidation product.

The oxidation product was dried by placing it in a vacuum over sulphuric acid for several days. The neutralization equivalent of this crude oxidation product was 157.

The oxidation product was heated on a watch crystal and the sublimate allowed to collect on a funnel. The first sublimate gave a melting point of 109 degrees Centigrade.

Combustions were made on this sublimate with the following results.

The neutralization equivalent was obtained by titrating an alcoholic solution of the sublimate with standard sodium hydroxide. The following results were obtained on two different lots of the sublimed oxidation product.

Using a third sample the neutralization equivalent was obtained from the analysis of the silver salt. The silver salt was formed by adding silver nitrate solution to a carefully neutralized solution of the sublimate. The insoluble silver salt was filtered off, washed with water to remove the excess of silver nitrate, and dried in a vacuum over sulphuric acid for several days. A weighed quantity of the silver salt was ignited in a platinum crucible and the residue of metallic silver was weighed. The following data were obtained using material from the same sample for each analysis.

Using the same sample, a neutralization equivalent was obtained by titration with standard NaOH.

The above data shows that the sublimate is a mixture. No empirical formula can be calculated from the combustions, and different samples give different neutralization equivalents although the duplicate determinations on the same sample showed good agreement thus demonstrating the reliability of the methods.

By fractional sublimation it was possible to obtain fractions with different melting points. The first sublimate melted sharply at 109 degrees. From the last fraction it was possible to separate some crystals that melt at 200 degrees Centigrade. These might possibly be p-acetyl-benzoic acid, as its properties of solubility, crystalline form, its melting point and power of sublimation agree with those of p-acetyl-benzoic acid.

Those crystals that appeared identical with benzoic acid were placed in a melting point tube, and some known benzoic acid (from toluol) was placed in another tube. These two tubes were placed in the same sulphuric acid container and their melting points taken at the same time. They melted at the same temperature.

The sublimate had a very pleasant aromatic odor resembling benzoin. It gave no coloration with ferric chloride, thus eliminating a large group of aromatic compounds. Some of the crystals were found to be identical with benzoic acid when examined under the microscope. The characteristic odor of methyl benzoate was produced when a small quantity of the crystals were heated with methyl alcohol and concentrated sulphuric acid. On treating some of the carefully neutralized product with ferric chloride solution, a flesh colored precipitate was formed. It agreed closely in its analysis with the precipitate formed with known benzoic acid.

The filtrate left after the removal of the iron precipitate was acidified and extracted with ether, and the ether removed by evaporation. The resulting substance decolorized alkaline permanganate solution, but did not decolorize bromine water. When the leaflet needles that melt at 200 degrees were mechanically removed from the original sublimate, the substance left after precipitating with ferric chloride melted at 109 degrees. When these crystals were not removed, the melting point of this material was not definite, but was over a range of five degrees, from 110 to 115 degrees Centigrade.

The oxidation product contains at least three distinct substances, benzoic acid, a substance melting at 200 degrees and—which is probably p-acetyl benzoic acid and a third substance melting at 110 degrees.