On the other hand, unadulterated oils with normal behavior as to specific gravity and solubility may be inferior because of their lower anethol content. Inasmuch as the value of the oil increases with its anethol content, and since the congealing point increases with the increased anethol content, the congealing point may be regarded as a direct measure of the value of the oil.
Determination of the Congealing Point. The method of determination is described in vol. I, p. 563. When drawing the sample care must be taken to ascertain that the entire contents of the canister are molten and well shaken1).
1 Report of Schimmel &Co. April 1897, 37.
2) E. ). Parry, Chemist and Druggist 77 (1910), 687. - ). C. Umney, Perfum. and Essent. Oil Record 1 (1910), 236. - H. R. Jensen, Pharmaceutical Journ. So (1910), 759.
3) Report of Schimmel &Co. April 1911, 110.
In order to obtain comparable results, the congealing should be induced when the thermometer registers 4 +10o.
Theoretically, the determination of the melting point of a staranise oil would be of like value as that of the congealing point. However, since the melting point of the staranise oil cannot be determined with anything like the same accuracy, the congealing point method is given preference.
The congealing point of a good staranise oil should not be below 15°. The Tonkin oil mostly has a higher congealing point.
Production and Commerce. The production of staranise is restricted to the Chinese districts Lungtschou (province Kwang-si), Pe-se (province Kwang-tung), on the border of Tonquin, and in the French colony Tonkin to the vicinity of Lang-son. Wutschou on the Si-kiang above Canton is the port of export for Chinese staranise2), for Tonkinese staranise Haiphong in Tonkin. As to the output of the Chinese districts, no statistics are available for recent years. In the nineties of the past century the output varied materially. Thus, in 1895 it amounted to but 1922 piculs (of 60 kg. each), whereas in 1892 it reached 16138 piculs. The bulk of it is shipped via Wutschou to Hongkong which place is the world's market for staranise. The exports amounted to:
1908: 14337 cwts. valued at 33 836 £ estimated at 2000 piculs (= 4000 cases of 30 kg. net content), is likewise shipped via Wutschou to Hongkong, which city is also the world's market for the oil. The oil distilled in Tonkin, which in recent years amounted to about 600 to 800 piculs, is shipped partly to China, partly sent by rail and steamer to Haiphong. The oil from the latter port is shipped principally to the mother country, France, being favored by special tariff regulations. The export of staranise oil from Tonkin amounted to1):
1909: 8188 „ „ „ 24 532 „
1910: 12 465 „ „ „ 38 685 „
1911: 15314 „ „ „ 33476 „
An even larger amount of staranise than is exported is utilized in the districts of production for the distillation of the staranise oil. The oil distilled in the Chinese districts3), which is 1908: 29000 kg. valued at 17 950 £ 1909: 50 000 „ „ „ 22 437 „
1) Oils that are not perfectly clear can be cooled below their congealing point only with difficulty. The suspended particles cause the oil to congeal as soon as the temperature has dropped a few degrees below the congealing point.
2) The Chinese harbor Pak-hoi which formerly exported almost exclusively staranise and staranise oil, appears to have turned over its entire trade in these articles to Wutschou.
3) The Chinese revenue statistics lump cassia oil and staranise oil. Hence without a knowledge of the ratio of the two, detailed figures are valueless.
The average imports at Hamburg during the last 12 years amounted to 36171 kg. Of this amount 6000 kg. were again exported. Via Hamburg, Germany imported the following quantities2):