How Science Happened to Me
Authors: ROBERT E. FORSTER
Journal: American Journal of Respiratory and Critical Care Medicine (2000)

The paper I choose to discuss is “Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries” ( J. Appl. Physiol. 1957;11:290– 302), by F. J. W. Roughton and me, the culminating article in a group of four, which described the separation of the resistance of carbon monoxide (CO) or oxygen (O 2 ) to diffusion in the pulmonary capillary blood from the resistance through the pulmonary alveolar membrane, as well as the measurement of pulmonary capillary blood volume, all in vivo . I was a medical house officer at the Peter Brent Brigham Hospital in Boston under George Thorn in 1944 when Dr. (Col.) John H. Talbott, commanding officer of the Quartermaster Corps Climatic Research Laboratory, located in the environmental chambers of the Pacific Mills in Lawrence, Mass., called to tell George that Clifford Barger, then at the Climatic Research Laboratory, had contracted tuberculosis so he needed a replacement, and did George know of anyone. Thus, in December of 1944 I found myself in an old New England mill town investigating heat loss from the extremities, temperature regulation, and the effectiveness of footwear and handwear in protecting soldiers under cold conditions. We had published some papers on peripheral blood flow and heat exchange by the end of World War II when I was discharged. I then used the GI Bill to study mathematics (of the baby type), physical chemistry, and physics at Harvard for a year before returning to take up a residency at the Peter Bent Brigham Hospital. After this I spent two years supported by a Life Insurance Fund, now defunct, as a post-doctoral fellow with Eugene Landis at the Harvard Department of Physiology, still working on temperature regulation, but by the hypothalamus in cats. I looked around for a faculty position in internal medicine, interviewed at Hopkins, where they thought I was applying for admission to medical school, when surprisingly I was offered a faculty position in the Graduate School of Medicine at Penn by Robert Dripps, director of anesthesiology, then in the Department of Surgery of the School of Medicine, and Julius Comroe, in the Department of Physiology and Pharmacology. The salary was handsome for the time, $6000, and Landis thought it indecently large, but I accepted. This changed my area of research from temperature regulation to respiration, through no intellectual initiative of my own. When I moved to Philadelphia, the Department of Physiology and Pharmacology of the Graduate School of Medicine was housed in a basement that flooded when it rained, but it had, or shortly gained, a remarkable faculty. Julius Comroe, Seymour Kety, Ward Fowler, Arthur DuBois and George Koelle were a few of the names, and there was a great excitement about the place. The philosophy was to apply the respiratory physiology that had been learned in the air and sea during World War II to the diagnosis and treatment of pulmonary diseases. Wallace Fenn had a similar philosophy for the founding of the Journal of Applied Physiology . I was assigned a small basement lab in the original School of Medicine building, with a new mass spectrometer and carbon monoxide (CO) analyzer, both of which had been ordered by Comroe with advice from Seymour Kety and John Lilly. The mass spectrometer was built to order from a low mass resolution (1 / 80) Instrument made by Consolidated Engineering Corporation to detect leaks in large capacity vacuum equipment. The CO meter was an infrared instrument, built to order by Max Liston, on a principle used by the Germans during World War II. Julius suggested that I repeat an experiment of Marie Krogh in 1914 that measured the diffusion capacity of the lung: the ability of the lung to exchange gases with capillary blood. In order to investigate the possibility of O 2 secretion in the lungs, she had measured the rate of disappearance of CO from the lungs during breath holding by inspiring a gas mixture containing a small amount of CO, immediately and rapidly breathing out an alveolar sample, holding the remaining lung gas for an additional 10 s, and then delivering a second alveolar sample into a rubber bag. The proportional drop in alveolar CO in 10 s plus the alveolar volume permitted her to calculate the pulmonary diffusing capacity for CO (D LCO ), a measure of the efficiency of the lungs in exchanging gas, defined as