A face velocity of 100 ft/s is equivalent to a 68 miles per hour, which would be a pretty good draft in the lab! While that velocity would certainly effectively remove the contaminated air, 100 feet per minute (~0.9 mph) is the proper figure for fume hoods, according to a recent check we did on our own hoods.

Editor’s Reply:

We thank you and other readers who caught our error in referencing a face velocity speed of 100 ft/s instead of 100 ft/min. Further, the use of a biological safety cabinet for the figure and opening art was the mistake of the editor and not the author. In both cases, we have made the correction on the Web version of the article.

Miracle Medicines|
Your article on sulfa drugs [“Miracle Medicines,” June 2001, p 59] oversimplified the role of the sulfonamides in chemotherapy. They did not disappear after the war but were important anti-infectives into the 1980s and are still widely used today. Sulfa drugs had a rebirth with the triple sulfas and soluble sulfas such as gantrisin and sulfamethoxazole. And the combination of trimethoprim–sulfa in Septra (Burroughs Wellcome) and Bactrim (Roche) helped overcome the resistance that every anti-infective is subjected to. Septra and Bactrim were certainly prominent and important anti-infectives until the end of the 1980s. Sulfa drugs are still prominent in Europe. Part of their falling out of use is commercial, owing to patent expiration and the desire to use newer drugs.

Author’s Reply:

I did not intend to imply that sulfa drugs disappeared after the war. I say toward the end of the column that the drugs “still play a role in modern medicine.” Just how important that role is relative to antibiotics and other drugs is a matter of judgment. Thank you for writing and expressing your opinion.

. . . and Taxonomy
I enjoyed your historical article “Miracle Medicines”. However, unless the taxonomy of the organism that produces syphilis has changed recently, it is a bacterium, not a protozoan, as the article states. Syphilis is caused by the spirochete Treponema pallidum subspecies pallidum. Trypanosomes, which are protozoans, produce diseases such as African sleeping sickness and Chagas’ disease.

. . . and More Taxonomy
The “Miracle Medicines” article is a sure way to inspire young microbiologists to extend their course of study into chemistry and biochemistry. No microbiology curriculum is complete without a firm understanding of the chemistry of life, and I too can trace my biochemical interest to the first reading of the Ehrlich “magic bullet” story.

Please try to print more of the same, but use careful editing. You sent me running to the latest issue of Bergey’s Manual to study the taxonomy change of Treponema. It’s hard enough to keep up with bacterial classification, but I feel sure now that Treponema is still a bacterium, and Plasodium is still a protozoan.

Home-Made Diamonds
I enjoyed your article on diamonds [“The Long Quest for Diamond Synthesis,” July 2001, p 63]. I have always been interested in the production of synthetic stones and have researched it (unsuccessfully) several times. I also have looked for general laboratory methods for making synthetic stones, and I realize that diamonds require very specialized equipment. Are there other stones that can be produced using more routine procedures, such as recrystallization, high-temperature fluxes, etc.? If so, I would appreciate a reference to the methodology.

Author’s Reply:

Unfortunately, I have no suggestions about references to the making of other synthetic stones, although an interesting book on diamond synthesis and high-pressure research is The New Alchemists: Breaking Through the Barriers of High Pressure, by Robert M. Hazen (Times Books: 1994).