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as high as 80 pounds. The usual calculation (4) was that eight good slaves could cultivate, harvest, extract, and prepare for the market the dye from 40 acres, “raise provisions besides and have the winter months to saw lumber.” The return for the crop depended upon the quality of the dye and the price varied from 30 cents to $2.25 per pound. It was said that a planter could double his capital in three to four years. One Georgia writer in 1751 (2) stated that the planters had brought the commodity somewhat into disrepute by attempting to produce quantity instead of quality. Cultivation after the Revolution
The cultivation of indigo grew rapidly once the planters realized the profits that i t yielded. There was a gradual increase in the production from the time of Miss Lucas’ experiments until just prior to the American Revolution, when the exportation reached the maximum. During the war it could not be classed as a “necessity,” and its culture was overshadowed by that of rice. After the war, with the market shattered and many of the plantations destroyed by the British, its cultivation was limited. One historian (8) states that “in 1783 indigo began to be cultivated again and 2051 casks were exported and continued to be a valuable export for several years.” George Washington, upon his visit to Georgia, entered in his diary on May 15, 1791, that “lumber and indigo are also exported but the latter is on the decline” (6). I n 1828-29 planters were encouraged to diversify their farming and plant indigo instead of cotton ( l a ) . It was cultivated to a comparatively small extent up to and during the Civil War, but most of it was consumed locally or “vended in the neighboring states.” I n 1848 there was published an account of the amount grown in one of the central districts (Orangeburg) of South Carolina ( 1 4 ) : YEAR 1831 1841 1842
AMOUNT PLANTED 953 1091 1337
POUNDS MADE 27,700 34,150 38.935
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The price ranged from 40 to 80 cents per pound. Causes for Decline of Indigo Culture
The principal causes for the decline of indigo culture are as follows: (1) England, upon the loss of the colonies, naturally discontinued paying the bounty on American indigo. (2) Soon after the Revolution, sea island cotton was introduced, 1786 in Georgia, and the planters turned their attention to its cultivation. Also, in 1792 the cotton gin was invented which stimulated the culture of that commodity. The preparation of cotton for the market did not demand any technical or skilled labor, and the plantations were free from the offensive odors associated with the indigo vats. (3) During the Revolution indigo was imported into Europe from the West Indies, as well as other countries, until it could be no longer profitably cultivated in the colonies. It is said that “indigo was more profitable to South Carolina than the mines of Mexico and Peru were to Spain.” Literature Cited (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16)
Colonial Records of Georgia, S, 696. Ibid., 26, 235. Ibid., Statutes, Colonial and Revolutionary, 1774-1805, 19, Pt 11, 33. “Description of South Carolina,” by order of Governor Glenn in 1761. Evans, “History of Georgia,” p. 44 (1900). Knight, “Georgia’s Landmarks, Memorials, and Legends,” Vol. 11, p. 103. McCall, “History of Georgia,” pp. 174, 209 (1811). McGrady, “History of South Carolina under the Proprietary Government,” p. 187. Ravenel, “Eliza Lucas Pinckney,” Scribner, 1896; Southern Agriculturist, 7, 514 (1834). Ross, IND. E m . CHEM.,14, 1153 (1922). Salley, “IntroduFtion of Rice into South Carolina,” Bulletin of H i s torical Commzssmn, 6 (1919), Columbia, S. C. Southern Agriculturist, 1, 484 (1828). I b i d , 2, 154 (1S29), gives description of dye extraction. Stevens, “History of Georgia,” 1,457. Tuomey, “Geology of South Carolina,” Appendix 23 (1848). Wallace, “South in Building of the Nation,” Vol. V. p. 178, Southern Historical Publication Society, Richmond, Va.
Explosion of Gasoline and Oxygen’ C. K. Francis SKELLYOIL COMPANY, TULSA,OKLA.
HE note of an explosion of cracked gasoline and oxygen in good condition, the oxygen valve was opened and the AND ENGINEERINQ published on page 473, INDUSTRIAL gas admitted until the gage registered 90 pounds, when it CHEMISTRY, May, 1930, suggests that notice of a similar explosion in our laboratories may be of interest and of value to others who are investigating the accelerated test for gum. We had a disastrous explosion of a bomb into which there had been placed 50 ml. of gasoline in a 4-ounce bottle. The gasoline was an experimental blend of straight run and cracked distillates, which had been caustic-washed and sweetened. The general quality of this product is shown by these tests: gravity, 55.1”A. P. I.; initial 100” F. (37.8” (2,); 10 per cent at 154” F. (67.8” C.); 20 per cent a t 188” F. (86.7” C.); end point, 420” F. (215.6” C.); gum, copper dish, 58 mg.; gum, steam oven, 2.8 mg.; doctor sweet. The bomb consisted of two parts, the bomb proper and a top, all of 3/&ch steel. The top was secured in place by means of six lag screws l / 2 inch in diameter and 11/4 inches long. A gage was connected directly to the top and there was an inlet opening which was connected with l14-inch pipe to the oxygen tank by means of a union. After the connections were made and everything appeared IBeceived June 20, 1930.
was discovered that the union was leaking. Then this first charge of oxygen was permitted to escape and the union made tight. Next the oxygen and inlet valves were slowly opened, but for some reason no pressure was indicated on the gage. After slightly jarring the gage by tapping, the oxygen and inlet valves were opened a little more, still without any pressure being registered. After again tapping the gage, the valves were opened further, when there was a terrific explosion with a ball of fire shooting up from the bomb. All the lag screws were broken and tbe top of the bomb with connections thrown some distance. The valve was shattered and the piping was torn open. The chemist working with the bomb was severely injured and burned, an operation of a serious nature being required. This explosion occurred in a small brick building, approximately 25 by 40 feet, with eight large windows, all of which were destroyed. We have decided that the oxygen-bomb test for potential gum formation offers too much hazard, and have consequently discontinued all investigations of this sort.
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