maltose vs sugar of milk

maltose

noun
  • A disaccharide, C₁₂H₂₂O₁₁ formed from the digestion of starch by amylase; is converted to glucose by maltase; it is an isomer of trehalose 

sugar of milk

noun
  • Lactose, a disaccharide found in milk. 

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