Karla Carson HT/HTL (ASCP), Regional Pathology Supervisor, Mercy Health Care, 
Sacramento, California asks:

<<So do we call Sodium Thiosulfate - Hypo because it is hypotonic?>>

The chemical name of sodium thiosulfate was changed from sodium hyposulfite 
many years ago (more than fifty, I shudder to reflect). Because of its 
widespread use in photographic development (to remove unreacted silver 
halide), photographers were wont to refer to it as "hypo".

Bob Richmond
Samurai Pathologist
Knoxville TN