An example of metaphor and simile in writing about science:
"The predecessors of Harvey had observed by cuts and ligatures the flow of the blood in the veins towards the heart not towards the outer parts of the body as their theory always took for granted. But they were so dominated by Galen that they said the blood behaved irregularly when it was tortured by such experiments – rushing off in the wrong direction like a fluttering frightened hen."
Herbert Butterfield (1957) The Origins of Modern Science 1300-1800 (New Edition: Revised and enlarged). G. Bell and Sons Ltd., London.
For a long period European medicine was dominated by the writings of Galen, which while an impressive body of work, include many historical notions that would now be seen as alternative conceptions. One of these was that blood moves in one sense – out from the heart, through the blood vessels, to the rest of the body. Harvey is widely recognised to have first convincing demonstrated blood circulation.
The point being made in the extract is that the influence of Galen's teaching about medicine was so strong that observations that should have contradicted it were either missed or explained away. Blood in veins moving towards the heart was explained away by arguing that what was seen during dissection (or indeed vivisection – where we might consider the poor experimental subject being tortured, not the blood *) could not be considered to reflect what actually happened normally in a healthy subject (an argument which in general terms has merits).
'Tortured' can be seen as a metaphor – arguably an anthropomorphic metaphor as only a feeling being can suffer torture.
The reference to the blood behaving like a fluttering frightened hen (which might run in a random direction) can be considered a simile.
Read about examples of science similes
* Vivisection, the dissection of still-living animals would allow observations while the heart was still actively pumping blood. While for long periods dissection of human corpses was banned in many countries (which has been argued to have delayed the development of knowledge of human anatomy and physiology) there are reports of human dissection, and even vivisection, being allowed when the subjects were condemned criminals.
