Ridgeon.  Well, theres nothing like progress, is there?

Sir Patrick.  Dont misunderstand me, my boy.  I’m not belittling your discovery.  Most discoveries are made regularly every fifteen years; and it’s fully a hundred and fifty since yours was made last.  Thats something to be proud of.  But your discovery’s not new.  It’s only inoculation.  My father practised inoculation until it was made criminal in eighteen-forty.  That broke the poor old man’s heart, Colly:  he died of it.  And now it turns out that my father was right after all.  Youve brought us back to inoculation.

Ridgeon.  I know nothing about smallpox.  My line is tuberculosis and typhoid and plague.  But of course the principle of all vaccines is the same.

Sir Patrick.  Tuberculosis?  M-m-m-m!  Youve found out how to cure consumption, eh?

Ridgeon.  I believe so.

Sir Patrick.  Ah yes.  It’s very interesting.  What is it the old cardinal says in Browning’s play?  “I have known four and twenty leaders of revolt.”  Well, Ive known over thirty men that found out how to cure consumption.  Why do people go on dying of it, Colly?  Devilment, I suppose.  There was my father’s old friend George Boddington of Sutton Coldfield.  He discovered the open-air cure in eighteen-forty.  He was ruined and driven out of his practice for only opening the windows; and now we wont let a consumptive patient have as much as a roof over his head.  Oh, it’s very very interesting to an old man.

Ridgeon.  You old cynic, you dont believe a bit in my discovery.

Sir Patrick.  No, no:  I dont go quite so far as that, Colly.  But still, you remember Jane Marsh?

Ridgeon.  Jane Marsh?  No.

Sir Patrick.  You dont!

Ridgeon.  No.

Sir Patrick.  You mean to tell me you dont remember the woman with the tuberculosis ulcer on her arm?

Ridgeon [enlightened] Oh, your washerwoman’s daughter.  Was her name Jane Marsh?  I forgot.

Sir Patrick.  Perhaps youve forgotten also that you undertook to cure her with Koch’s tuberculin.

Ridgeon.  And instead of curing her, it rotted her arm right off.  Yes:  I remember.  Poor Jane!  However, she makes a good living out of that arm now by shewing it at medical lectures.

Sir Patrick.  Still, that wasnt quite what you intended, was it?

Ridgeon.  I took my chance of it.

Sir Patrick.  Jane did, you mean.

Ridgeon.  Well, it’s always the patient who has to take the chance when an experiment is necessary.  And we can find out nothing without experiment.

Sir Patrick.  What did you find out from Jane’s case?

Ridgeon.  I found out that the inoculation that ought to cure sometimes kills.