The meaning of the word ‘dialysate’ as defined in the Oxford Dictionary is indeed apt to induce mental confusion. It did so recently in my own mind, when I had to struggle through an American patent specification, in which the term was actually used in its Oxford Dictionary sense. In my opinion, as well as in that of my collaborators, Dr. Pirie is quite right, and his discussion1 supports our decision to use the term ‘dialysate’ for the part which dialyses through the membrane.