Re: tasting chemicals

["Dept of Radiography, Canterbury Christ Church College" <c.d.jeffery@canterbury.ac.uk>]

> I guess I've reached the age where one dislikes admitting to retrospecively 'stupid' things.  But I seem to 
>recall in my chemistry classes of my youth that when one had positive knowledge of a chemical stew that it 
>was not unusual to 'taste' or even sniff vapors for identification purposes.  I even remember (horror of 
>horrors) doing mouth pipetting.  While our current safety standards render such practices today as 'stupid' is 
>it appropriate to describe accepted practices of more than 30 yrs ago in that manner?

While I don't advocate tasting chemicals and sniffing vapours it is still true that a number of film processing 
errors can be identified using our own senses. Sulphiding in silver recovery units is a very distinctive odour, 
and the conversion of the insoluble silver ammonium thiosulphate to soluble silver ammonium dithiosulphate 
is accompanied by a change in taste of the film emulsion from sweet to tasteless.


Chris Jeffery
Senior Lecturer in Radiation Science
Canterbury Christ Church College,   UK