So Venkat started working on this stuff and then... and he did a lot of isolations and... and then we had to get an experimental animal to test it. Well, there isn't really an experimental animal for... for hepatitis B because — well, there are, but they're non-human primates. Well, they're... I, number one, didn't like working with primates and first of all, you know, it's hopelessly expensive, you know, to even begin to think of doing that, but there's the strange business about woodchuck hepatitis virus and I’d... you know, since I was interested in kind of the evolution of the virus, very early on we started looking for... we started looking for the virus that would react with the antibody, looked for... in other animals, and we also wanted to find an animal we could use to... to inoculate, you know. We wanted to get an experimental animal, so we surveyed 25–30 species of animals. A lot of them was serum that I collected up in Alaska, you know, seals in the Aleutians and... and stuff from West Africa and... and material I got from the zoo. Tested a lot of chimpanzees — the blood not the animals themselves. Well, it turns out you do find in... in higher apes and in vervets and squirrel monkeys, but it's in chimpanzees and gorillas and orangutans and... but we weren't going to use those experimentally. But I kept looking in other places and there were some clues but... but about that time Jesse Summers came here. You remember Jesse of course? And Jesse had been working - he's a virologist, a molecular virologist - so he was looking for, he wanted to find an animal that he could use for inoculation studies. So he got it in his head that he wanted to work with fish. Well, I think one of the reasons was he likes fishing, but fish wasn't a good choice. At about that time we had been visiting the zoo quite often because we'd been given a... a gibbon by one of the pharmaceutical companies who, they found it had hepatitis B virus and they didn't want to retain it so they thought we might use it and we couldn't keep it here obviously so we, it was kept in a... in the... in a sort of separated primate place in... at the zoo. It was very well looked after. But we never did, you know, we collected blood from it occasionally but I didn't... it was a beautiful animal. But in any case I used to go down and see him every so often to see how things were going and then I got to know Dr Snyder who was in charge of the pathology and research lab in the zoo, and I told him we were working, you know, on cancer of the liver. He said, ‘Cancer of the liver? Oh, I see plenty of that in woodchucks’.  And he had done his thesis on gender ratio in woodchucks by the way, and he had a colony of woodchucks. And he found that a very large percent of them, if they lived five years or more and didn't die for other reasons, most of them died through cancer of the liver. And then he studied them in the wild as well where you don't see cancer of the liver so much but... but animals that live in, woodchucks live in the wild don't live as long — anything like as long — as woodchucks that live in the zoo but if you corrected it for age, then the prevalence in the wild was... was about the same, as in the zoo. So that meant here was an animal with this incredible high prevalence of primary cancer of the liver which pathologically looked an awful lot like the cancer of the liver in humans.

[Q] And were they infected?

Well, we couldn't find any using the serological techniques but we brought back... Tom got some and gave it to Jesse and that's where he found woodchuck hepatitis virus and they... and they...

[Q] So it didn’t just cross-react with the human...?

It... it did in fact partially but you couldn't... initially you couldn't detect it that way but you could detect it using... it would affect molecular too, a much more sensitive method and then... then, well, I went to China, that was another important trip that I told you about and when I was there, Dr Sun, my colleague, who was interested in hepatitis — we were chatting, you know, we used to go for walks in the evening — and we started chatting and he said, ‘You know, there... the domestic ducks in a part of the country where we have a lot of cancer of the liver, they have a lot of cancer of the liver’. So I got some of the blood from the ducks and brought it back to Jesse. In the meanwhile, Dr Sun went ahead. He... he identified the virus in the ducks and in time Jesse did too and he actually found it in domestic ducks here in so-called... in a breed of ducks called Peking ducks that were originally imported from China. So then he did a lot of, you know, a lot of the molecular biology, the replication studies were done on the ducks and the woodchucks as well. So that's how that, you know, Jesse being here interested in the sort of availability of these... these kind of strange species that we... we had about them, you know. It... it shows you how you kind of get an idea, then you test it, you know, but you have to make the observation. If I hadn't been, you know, doing fieldwork in China, I probably, I wouldn't have heard that.

[Q] And did you go on to use the woodchucks in your therapeutic studies?

Yes, and we had a woodchuck colony over here but, you know, I soon... I soon realized that we really weren't equipped to do this kind of therapeutic research. Now, I... I was... I arrived at that conclusion reluctantly but in a funny way I should have perceived it early on.

Well, actually a lot of work's been done with phyllanthus. It's... the plant is widely used independent of any findings we had. The initial studies we did were very suggestive that it was effective, but they weren't confirmed, you know, and in science if you can't confirm it, it's the equivalent of it not having happened, even... even though the initial observations may have been correct. And we spent a lot of time trying to get drug companies interested, which is tiresome work you know, and... and not very gratifying, but in any case, I spent... I spent several years working on this, probably the... the least ‘successful’, quotation marks, research I've done, but people are still working on it, and there were leads, you know, in the laboratory level it has, it does have an effect, and it's conceivable that some use may come of it some time in the future. These things often take a long time. But the plant collecting was interesting. I'm just... I have a herbarium, you know, with the plants, I'm about to donate it to the Academy of Natural Sciences.

[Q] Oh, that's wonderful.

Well, you know, we don't need it here of course and otherwise I'm afraid it would get... but they may be able to make some use of it.