lava vs magma

lava

noun
  • The molten rock ejected by a volcano from its crater or fissured sides. 

  • Magma. 

  • A shade of red, named after the volcanic lava. 

magma

noun
  • The molten matter within the earth, the source of the material of lava flows, dikes of eruptive rocks, etc. 

  • The residuum after expressing the juice from fruits. 

  • A basic algebraic structure consisting of a set equipped with a single binary operation. 

  • Any soft doughy mass. 

How often have the words lava and magma occurred in a corpus of books? (source: Google Ngram Viewer )