The Coulter principle: Imaginary origins

IN the opening session of CYTO 2013 a spokeswoman for the Wallace H. Coulter Foundation summarized from the podium a story, styled as an urban legend true so far as was known, of Wallace Coulter working toward sizing pigment particles but finding his paint sample frozen. He then supposedly thought of the similar viscosity of paint and blood before first demonstrating the Coulter Principle using his own blood. This requires Wallace being ignorant of the commonly-known disparity between the viscosities of paint and blood, and several listeners subsequently asked me if this story could be true. An undocumented story of the Coulter Principle originating in Wallace’s working to improve Navy paint materialized on the Foundation’s website (1) and was a Foundation contribution to Volume 10 of the Purdue Cytometry Disc Series (2). It appeared as a Wikipedia article (3) when it replaced a story claiming that Wallace joined the US Navy during World War II and created a device to count plankton that would become the basis for the Coulter Principle (4); variants of the plankton story have since appeared (5,6). Other versions of the paint story were posted by the Foundation’s spokeswoman on a second website (7) and published by the Foundation (8), by a past president of the CYTO 2013 sponsor (9), and in a second book with acknowledgement to the Foundation (10). Although each of these stories poses its origin for the Coulter Principle as unqualified fact, they juxtapose disconnected sentences lacking details necessary for a historical narrative and so misguide an uncritical reader to assume details only implied, not actually stated. Wallace neither joined the Navy nor worked as its civilian employee, and he first documented the Coulter Principle in July 1948 before demonstrating it with, neither plankton nor paint, but “blood greatly diluted” in October 1948 (Fig. 1a). Wallace later reaffirmed (11) using blood in his first demonstration of the Coulter Principle (second note by Walter R. Hogg, Fig. 1b): “When we started we didn’t have much money, so we made an aperture by making a small hole with a hot needle in a piece of cellophane from a cigarette package. It didn’t hold up long, but we were able to count some cells.” Wallace’s pre-war visits to hospitals in the Far East had made him aware of the many hours spent by medical technologists doing chamber counts of blood cells, and he studied papers regarding the method’s poor accuracy and repeatability. The aftermath of the August 1945 atomic bombings of Hiroshima and Nagasaki made Wallace truly understand the need for rapid and accurate red-cell concentrations, not just occasionally for individuals, but repeatedly for members of whole populations as an index of recovery from radiation exposure. His conviction was evident in our conversations about those bombings, which he usually concluded with, “It’s the worst mistake this country ever made.” After their purchase of a Chicago house in April 1947, he and his brother, Joseph R. Coulter, Jr., began experimenting in their basement with Moldavan’s suggestion for photo-electrically counting blood cells flowing through a capillary tube (12), but found the author’s criticisms of the method justified. The Coulter brothers then tried detecting cells with the microscope positioned so that the photo-detector viewed axially along the capillary bore rather than across the bore through the capillary wall. By late 1947 Wallace had reduced the capillary tube to its minimum length (11), but still was unable to count individual cells. In July 1948 he found a brief note (13) that focused his efforts on miniaturizing conductivity cells. The Coulter Principle, first illustrated in Figure 1, is the result. Wallace’s emphasis was on accuracy rather than neatness, and his description of the October 30 demonstration in Figure 1 is typically difficult to follow. As indicated in the upper sketch, with a hot needle he burned a hole about 0.003 inch [76 mm] in diameter in a piece of cellulose acetate 0.00088 inch [22 mm] thick, secured it to the short end of the “J” tube with rubber bands, filled the “J” tube with his blood diluted several thousand times in 0.9% NaCl solution (Fig. 1b), immersed the crook of the “J” tube in a container of 0.9% NaCl, and connected a preamplifier driving an oscilloscope to