RIDGEON. They do when you butter them with opsonin.
SIR PATRICK. Gammon.
RIDGEON. No: it’s not gammon. What it comes to in practice is this. The phagocytes wont eat the microbes unless the microbes are nicely buttered for them. Well, the patient manufactures the butter for himself all right; but my discovery is that the manufacture of that butter, which I call opsonin, goes on in the system by ups and downs—Nature being always rhythmical, you know—and that what the inoculation does is to stimulate the ups or downs, as the case may be. If we had inoculated Jane Marsh when her butter factory was on the up-grade, we should have cured her arm. But we got in on the downgrade and lost her arm for her. I call the up-grade the positive phase and the down-grade the negative phase. Everything depends on your inoculating at the right moment. Inoculate when the patient is in the negative phase and you kill: inoculate when the patient is in the positive phase and you cure.
SIR PATRICK. And pray how are you to know whether the patient is in the positive or the negative phase?
RIDGEON. Send a drop of the patient’s blood to the laboratory at St. Anne’s; and in fifteen minutes I’ll give you his opsonin index in figures. If the figure is one, inoculate and cure: if it’s under point eight, inoculate and kill. Thats my discovery: the most important that has been made since Harvey discovered the circulation of the blood. My tuberculosis patients dont die now.
SIR PATRICK. And mine do when my inoculation catches them in the negative phase, as you call it. Eh?
RIDGEON. Precisely. To inject a vaccine into a patient without first testing his opsonin is as near murder as a respectable practitioner can get. If I wanted to kill a man I should kill him that way.
EMMY [looking in] Will you see a lady that wants her husband’s lungs cured?
RIDGEON [impatiently] No. Havnt I told you I will see nobody? [To Sir Patrick] I live in a state of siege ever since it got about that I’m a magician who can cure consumption with a drop of serum. [To Emmy] Dont come to me again about people who have no appointments. I tell you I can see nobody.
EMMY. Well, I’ll tell her to wait a bit.