On Wed, 13 Oct 1999, John Difford (Royal Free) wrote:

> John Kiernan has stated in a recent communication to Histonet that when
> naming a formaldehyde-containing fixative the correct usage is formal- 
> (as in formal-saline) and he cites J. R. Baker as the authority for this
> view.
> 
> 1. Baker did not approve of the use of formol-, that  is true, but then
>    he did not approve of formal- either. Read his book for the reasons.

   Thanks for the correction. Baker's book was but a foot from my right
   hand when I typed my little ditty, but being left-handed I didn't
   actually bother to check what I incorrectly thought I remembered.

> 2. The first person to describe the effect of formaldehyde solution as a
> fixative for tissues was Ferdinand Blum (in 1893)...

   This was a discovery like anaesthesia that wasted no time 
   getting around the world. In 1895 Pierre Fish (an American
   pathologist) published a zinc-formalin mixture for fixing
   brains, and his paper had 3 or 4 references to 1894 papers
   on formaldehyde fixation. The wheel, once invented, gets
   reinvented again and again and again.  
>                                            ... He [Blum] was using
>  a commercially produced solution called ' Formol' ...
>  Hence, since Blum was the first to describe Formol- as a fixative,
>  we should give him priority in the manner of naming.

   Walker's "Formaldehyde," 3rd ed., (1964) says Formalin and Formol
   were European trade-names for the concentrated solution (Chap 4).
   Formals are compounds with -CH2-O-CH2- (ether-like) linkages, and
   the term embraces the many compounds, including the product of
   reaction with 2 methanol molecules (= methylal; also called formal
   or dimethoxymethane). Larger (polymeric) formals are more rapidly
   hydrolysed than smaller ones, but even methylal is in equilibrium
   with methanol, water and methylene glycol (Chap 10). This is
   why polymer formation is inhibited by putting some methanol in
   a strong aqueous formaldehyde solution such as formalin. (For this
   I did check in the book.)
   
   It really doesn't matter much, but formal- may be more appropriate
   chemically, if not historically, than formol-.  This is all a bit
   silly really, because form?l-saline has long been superceded by
   better solutions such as the many NBFs and form?l-calciums.    
    
   An -al ending seems better for an aldehyde than -ol, which
   seems to signify an alcohol or a phenol. I rest my case.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1
   Phone: (519) 661-2111  <-- NEW NUMBER
   FAX (Department): (519) 661-3936
   E-mail: kiernan@uwo.ca