Biology

Abstract

HISTOLOGICAL technique was once a mere rule-of-thumb affair, and there are some to whom it is so still! One stain gave red, another blue; one stained the nucleus, another cellulose; but how or why was no concern of the histologist so long as the result seemed good. But following Sir William Hardy's lead, men began to wonder how much of all their pretty preparations was artefact; and then came a growing desire to understand the rationale of fixing, staining and clearing in their chemical and physical relation to the colloids of the cell. So the histologist began to learn from the dyer the difference betweon an acid and a basic dye, and was some way along the road to skill and wisdom by the time he understood, for example, that a red blood-corpuscle was permeable to anions, and that eosin was, ipso facto, an appropriate dye.