訂正日: 2008/11/27訂正理由: -訂正箇所: 論文抄録訂正内容: Wrong : 20g of the nitrated cotton, which were washed with water after nitration to free from acid, were boiled with distilled water of 80 times of their weight in a hard alkali free glass flask with a reflux condenser. After they were boiled 40-80 hours, the water being changed 4-6 times, the water became nearly neutral to phenolphthalein, indicating that acid residue was entirely extracted. At the same time, the specific electrical conductivity became nearly constant, reaching a minimum value of (0.3-0.5)×10-4, and the ignition point of the cellulose nitrate became to a constant value of 182°C. The value of the conductivity however is higher than that of the water used for boiling, which was 4.2×10-6 by a blank test. It is supposed that the mineral salts contained in cellulose nitrate and the decomposition products of the unstable cellulose nitrate are extracted as long as the boiling is continued, giving a high conductivity. The ignition point of cellulose nitrate did not become higher than 182°C, as the boiling was continued, while the Abel heat test became higher along with the boiling, the cause of which can be easily understand if the mechanisms of both reactions are considered. Sulphuric acid content in cellulose nitrate became to about 0.01 or somewhat lower, but this residue of sulphuric acid seems to exist as salt. The instability of cellulose nitrate after the unstable acid residue is removed, is caused certainly by the presense of the unstable cellulose nitrate such as the lower nitrate or the nitrate of oxdized or hydrolyzed cellulose. The nitrogen content of cellulose nitrate increased or decreased in an irregular manner along with the boiling, which may be attributed to that the decomposition of the various nitrates of cellulose occured in various stages of boiling. The electrical conductivity of the boiling water can be used as a means of measuring the degree of the purification of cellulose nitrate, but it can not suggest the properties of the cellulose nitrate after the stability reached to a certain point.