[Illustration: Aleurites Fordii Flowering specimen of the Chinese Wood Oil tree, thirty feet high and three feet in diameter, on banks of Yangtse River, Western Szechuan, China. Opium Poppy in the foreground] [Illustration: Aleurites Cordata Wood Oil tree at Riverside, California, planted in 1907. Photograph taken in 1910, when tree had borne fifty fruits] During the boiling of raw tung oil the temperature must not exceed much over 400 degrees Fahrenheit. Otherwise a peculiar "hamming" will take place, the whole mass becoming solid and of no further value as a varnish or paint vehicle. Some peculiar internal disturbance or rearrangement of the molecules is evidently effected by heat, and although the reaction is not clearly understood, it has been ascribed to auto-polymerization. Scott has stated that the phenomenon of gelatinization is due to the exposure of the surface of the oil to the air, and that boiling in vacuo obviates such results. The lusterless surface produced when tung oil varnishes are dried in vitiated air would tend to confirm the conclusion that the oil is very subject to atmospheric influences. Lumbang Oil, which is obtained from a tropical species of Tung, is very similar in appearance and properties to Linseed Oil. CONSTANTS OF TUNG OILS =====+=========+============+==============+========== | Sp. Gr. | Iodine No. |Saponification| Acid No. | | | No. | -----+---------+------------+--------------+---------- No. 1| .944 | 166 | 188 | 3.6 No. 2| .940 | 164 | 184 | 1.8 =====+=========+============+==============+========== [Illustration: _Photographs courtesy Alpin I. Dunn_ Menhaden Net drying in the Sun] [Illustration: Transporting Menhaden from net to deck of boat, in swinging basket] [Illustration: A big catch of Menhaden made off Narragansett Bay]