Red lead is made by heating litharge to a suitable temperature after the litharge has been cooled, ground, and purified. The heating is done in a reverberatory furnace where, at about 900° F., the buff-colored powdered litharge takes on more oxygen, changing in color to a brilliant red. This is red lead. The conversion takes about 48 hours. A peculiar phenomenon is that if the temperature is raised to 1,100° F. and higher, the red lead loses oxygen and reverts to litharge.

Orange mineral is made in the same way as red lead and litharge except that the process starts with white lead instead of pig lead. White lead is roasted in a furnace and turns to orange mineral as it takes in oxygen and releases carbon and hydrogen.

Basic lead sulphate is made from lead ore that contains zinc minerals in addition to galena. The process of manufacture consists in crushing, washing, and separating the minerals from associated rock by a gravity or "jigging" process, termed concentrating. The concentrates thus obtained are subjected to blast-furnace treatment in which volatilization takes place, and the volatilized portion of the concentrates are oxidized. The result is a white fume which is carried away by a draft of air and collected in bags. Blue basic lead sulphate is a by-product obtained in the above process. The lampblack which colors it is an accidental ingredient resulting from incomplete combustion of carbon fuel used in the blast furnace.

WILLIAM CRAWFORD GORGAS.1

By Brig. Gen. ROBERT E. NOBLE.

[With 1 plate.]

So much has been written about the life and work of Gen. William Crawford Gorgas, that whatever the writer may say will be much like repeating in new words facts that are already well known.

Intimacy with such a man does not always lead to ease in speaking or writing of his personality or of his work, for there may be feeling that represses rather than causes an easy flow of words.

Intimate association for more than 13 years, with this, the most knightly man that I have ever known, leaves me when I hear others speak of him, almost dumb. I listen, I think of him, of the great things he has accomplished and accomplished in the face of opposition and of a disbelief in him and in his methods, and finally of the acknowledgment by many of those who had opposed him that he was right, of the adoption of his methods by men and nations, of the lives he has saved, of the men yet unborn who because of his teachings will be conserved to the world, and finally of his end, while he was yet able to give to the world a service that would benefit mankind.

He was freeing the world from yellow fever, a disease that has taken its toll from both hemispheres, that has been epidemic for centuries in Central and South America and in the West Indies; a disease that has paralyzed commerce and has caused panic and disaster in the Southern States; a disease, which as a result of the practical application by General Gorgas of the discovery by the Reed Board that yellow fever is transmitted by a mosquito, and by only one mosquito, the Stegomyia fasciata, is now confined to a few endemic and epidemic centers, and which in five years will be eliminated from the earth.

General Gorgas was born at Mobile, Ala., October 3, 1854, the son of Gen. Josiah and Amelia Gayle Gorgas. He was educated in private schools until he entered the University of the South, graduating with an A. B. degree in 1875. Deciding to study medicine,

1 Reprinted by permission from the American Journal of Public Health, March, 1921.

he entered Bellevue Hospital Medical College, graduating in 1879. He served as interne, 1878-1880, and was commissioned as a first lieutenant and assistant surgeon in the Army, June 16, 1880. His first assignment to duty was at Fort Clark, Tex. In the fall of 1882 he was ordered to Fort Brown, Tex. Here he had his first professional experience with yellow fever, then epidemic on the Mexican border. This experience with this scourge so early in his career largely influenced his future. The mystery of its spread and its deadly nature appealed to his imagination, and he lost no opportunity to study this disease, and such opportunities were not infrequent for those who served at any of the stations located in the Gulf States, where yellow fever was from time to time epidemic. His cases were always carefully observed. Methods of treatment, hypotheses regarding the transmission of infection from man to man, and the various methods proposed for the control of epidemics, were studied and tested. All that he learned, or a supposition disproved, was a stimulus for greater effort. Further observation was temporarily interrupted in the fall of 1884 by reason of his transfer from Fort Brown to Fort Randall, Dak.

On June 16, 1885, he was promoted to the grade of captain and assistant surgeon. On Sept. 15, 1885, he married Miss Marie Cook Doughty of Cincinnati. Opportunity to resume the study of yellow fever came with his transfer to Fort Barrancas, Fla., where he served, with the exception of an 18-month tour of duty at Fort Reno, until the war with Spain. Shortly after the outbreak of the Spanish-American War he was appointed major and brigade surgeon. A vacancy in the regular service permitted of his promotion July 6, 1918, to the grade of major and surgeon in the regular establishment.

General Gorgas went to Siboney on the hospital ship Relief, and was present during the entire Santiago campaign. He established and was in command of the yellow-fever hospital at this place. He was invalided to the States after the occupation of Santiago, because of a severe malarial infection. After convalescence, he returned to Cuba, and was made health officer of Havana.

Here yellow fever was epidemic as it had been almost continuously since 1620. Havana was cleaned, one might say scrubbed and disinfected, but yellow fever remained. Case after case was found. No method tried served to lessen the incidence of the disease. The Reed Board was investigating theories advanced regarding the etiology of that disease. Their work was notable in proving that none of the etiological factors claimed by their sponsors was the true cause of the disease. The claim put forward by Dr. Carlos Finlay in 1881, that the Stegomyia fasciata was the agent by which the yellow-fever virus was transmitted from man to man alone remained. On Febru