cryogeny vs natural philosophy

cryogeny and natural philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
cryogeny	Yes	No	No	No
natural philosophy	Yes	No	No	No

As nouns, natural philosophy is a hypernym of cryogeny; that is, natural philosophy is a word with a broader meaning than cryogeny:

cryogeny: the branch of physics that studies the phenomena that occur at very low temperatures
natural philosophy: the science of matter and energy and their interactions

Other hypernyms of cryogeny include physics.

cryogeny (noun)	natural philosophy (noun)
the branch of physics that studies the phenomena that occur at very low temperatures	the science of matter and energy and their interactions