From the first crystallization, 8. 5 kilograms. From the second crystallization, 3. 4 kilograms. From the third crystallization, 2. z kilograms. From the fourth crystallization, I 5 kilograms (crystals A)

No abstract

After separating columbium from tantalum and other constituents by fractional crystallization of complex salts and fractionation of metal chlorides at elevated temperature, a very pure columbium oxide is obtained. A new process for reducing this oxide to pure columbium metal is described. This method is based on the fact that, when an intimate mixture of columbium carbide and columbium oxide is heated in a vacuum, columbium metal is produced. This is then converted to columbium metal powder and into columbium metal bars by powder metallurgy. A white, soft, ductile metal is finally obtained whose applications are briefly considered.

Part of a thesis submitted by Edward Wichers to the Graduate School of the University of Illinois as partial fulfillment of the requirements for the degree of Doctor of Philosophy.

I 140 CLAREKCE W. BALKE.Guanidine acetate, used instead of the thiocyanate, gave the same condensation-product.An attempt was made to prepare the naphttetrazine by direct fusion of succinylosuccinic ester and guanidine acetate, in the same way that the diimine was made from succinylosuccinic ester and ammonium acetate, but no condensation occurred.Finally, a solution of free guanidine was prepared from the carbonate and condensed with succinylosuccinic ester, but this variation showed no adrantage over the use of a guanidine salt and sodium ethylate either in the yield or purity of the product.