What herbs and ingredients were used to treat more common diseases or discomforts like headaches or fever? I'd also like to know what they did to your body and what diseases/discomforts they cured or eased and how they were consumed.
Medicines from the golden age of piracy are an incredibly complex topic. There is an extensively sourced article on my website that discusses about half of the medicines that sea-surgeon John Woodall advised a surgeon bring with him, how they were made and what they could be used for here: http://www.piratesurgeon.com/pages/surgeon_pages/woodalls_medchest1.html
That article contains 160 medicines that Woodall showed locations for in his long-voyage medicine chest designed for the East India trading company. I am currently working on a counterpart article to that one about the medicines he suggested the surgeon might carry with him, but which he didn't give specific locations for in his medicine chest. This article will include an additional 150 medicines, several of which could be used for headaches and fevers.
Taken together, Woodall suggests 310 medicines in his book that might be of use to a surgeon at sea! And there is a great deal of overlap in the uses for the various medicines.
In the article on my site the things that might be used for headaches include Diascordium, Conserve of Roses, Aqua Absinthi [Wormwood water], Aqua Rosarum [Rose water], Oleum Anethi [Oil of Dill], Aqua Cardui Benedicti [Water of Blessed Thistle], Oleum Succini [Oil of Amber], Theriaca Andromachi [Venice Treacle], Laudanum Paracelsi Opiatum [Paracelsus' Recipe for Laudanum], Electuarium Diacathelicon, Camphora [Camphor] and Opium. Fevers have just as many or more possible cures. And that's just drawing on HALF of Woodall's suggested medicines! (The second article is not finished, so it would be difficult to include in my list of headache remedies.)
Most of these things (other than the opiates) were probably of limited efficacy, but they were primarily natural and so probably had limited side effects. [Although it depended on the ingredients, of course.] As for how they were consumed, the above list includes a lot of jellies (conserves), waters and oils for head-aches and fevers, which would have primarily been internally administered.
Other sea-surgeon authors suggested similiar medicines, although not quite as many of them. I talk about this in the first few pages of that article I link to.
Sorry I can't be more specific, but I hope that helps answer your question. Check out the article on my web page for more insight.
Hey Peppedeluxe, I don't know if you're still paying attention to this, but I got another inquiry on how to treat headaches last month, so I decided to go ahead and put together an article on the topic. I plan to do one on fevers eventually, but that's a much, much larger topic and is probably a long ways off.
http://www.piratesurgeon.com/pages/surgeon_pages/headaches1.html