“I read an article about science finding an ancient body that suffered from cancer. Upon mentioning this to a friend of mine, he replied that, “Yes, that it is true, some people did have cancer long ago, but only those people who chose not to go to an alchemist”. When I expressed disbelief about his statement, he replied that long ago, alchemists were able to cure people of all forms of diseases by using alchemy. Then, he rapidly listed names and dates. He seemed quite knowledgeable and genuine”.

Well, Alchemy did have some silliness to it. Like people believing they could use alchemy to turn minerals into gold and silver. But Alchemy did lead to chemistry, and took the first real steps in developing medicine.

As for the cancer claim, that isn't really true. Cancer rates were lower years ago because of lower carcinogens in the environment and people not having long enough life spans to develop cancer. And there is no real evidence that before the 17th century that alchemist actually cured anything. Although many people did go to Alchemist for remedies.

Alchemy - Wikipedia, the free encyclopedia

I don't often use wiki for source material, but this is actually pretty good.