In further study it has been found that no matter what compression is used, providing there is no disintegration, the corkwood will retain just that slight spongy character that so marks its growth. In analyzing this solid matter, Ure found by treating it with nitric acid the yielding was: White fibrous matter (cellulose). 0.18 parts Resin ........................... 14.72 “ Oxalic acid ..................... 16.00 “ Suberic acid .................... 14.4 “ ─────────── 45.30 parts Chevruel in an analysis of corkwood states that he found the following constitutents, but he does not give percentages: Cerin, a soft fragrant resin. Yellow and red coloring matter. Quercitannic acid. Gallic acid. A brown nitrogenous substance. Salts of vegetable acids. Calcium. Water. Suberic acid. Suberin (cellulose). I am inclined to think that Chevruel selected a poor grade of cork, full of stone cells and Jasperado, as his findings include much that would indicate that was the case. In further defining the various substances which go to make up the body of corkwood the one that is most impressive is that substance that is peculiar to cork itself, the others being readily known, but suberic acid is the one of interest, and this is described by Fownes as a product of the oxidation of cork by nitric acid; is a white crystalline powder, sparingly soluble in cold water, fusible and volatile by heat, the chemical formula given being (C_{4}H_{14}O_{4}). Suberic acid is also described as a dibasic acid which forms small granular crystals very soluble in boiling water, alcohol and ether. It fuses at 300 degrees Fahrenheit and sublimes in acidular crystals. It is also produced when nitric acid acts on stearic, margaric or oleic acid. The chemical analysis is given as (C_{8}H_{14}O_{4}) and I am inclined to believe it is the truer one, as it is much later than Fownes’. This suberic acid has been further broken up to ascertain its fundamental characteristics and it was found to partake of the two compounds suberone and suberate. Suberone (C_{14}H_{24}O_{2}) being regarded as the ketone of suberic acid, an aromatic liquid compound obtained when suberic acid is distilled with an excess of lime.[24] Also described as a colorless oil with an odor of peppermint and a boiling point of 179 to 181 degrees Centigrade, chemical formula, Suberone—Cycloheptanone— CH_{2} . CH_{2} . CH_{2} / CO \ CH_{2} . CH_{2} . CH_{2} [24] “Standard Dictionary.”