A recent study from the research labs of Johns Hopkins University brings to mind the earlier days of medicine, a time in which there existed a serious premise called the Doctrine of Signatures. It was believed that those plant materials that in some manner resembled parts of the body would be useful in treating those same organs. Paracelsus is often given credit for originating this concept. Andrew White in his 1896 treatise on the ‘warfare of science with theology’ summed it up like this:
"It was reasoned that the Almighty must have set his sign upon the various means of curing disease which he provided; hence it was held that bloodroot, on account of its red juice, is good for the blood; liverwort, having a leaf like the liver, cures diseases of the liver; eyebright, being marked with a spot like an eye, …. "