Sentence:  When the stain is of recent date, or supposed to be so, the red corpuscles should be particularly examined, and every care should be taken to preserve them without change. The stains must not be washed with water, so that the <WSD>hæmatin</WSD> may not be altered. 
Meaning of the word marked with <WSD> tags:  Hemoglobin with iron in ferric state.