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. Wt. of container 6.7220 Wt. of container and substance 7.5920 Wt. of substance .8700 Wt. of oxidation product .1240 Percent yield 14% 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. Wt. of substance used .0502 Number Cc. of NaOH N/10 3.2 cc. Neutralization equivalent 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. (1) C 66% H 4.7% (2) C 65.7% H 4.8% (3) C 65.15% H 4.8% (4) C 65.8% H 4.85% 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. Wt. of substance .09 .1006 Cc. of alkali N/10 7 cc 7.9cc Neutralization equiv. 128.6 127.3 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.