A Quick check of some web resources gives:
http://en.wikipedia.org/wiki/Rum_ration
	Generic article on the issue of rum
http://en.wikipedia.org/wiki/Black_Tot_Day
	Last issue of run in the RN, with potted history
http://www.spiritshop.co.nz/rum.html
	Generic article on rum
http://collections.soundarchives.co.nz/search.do;jsessionid=omT5hJH+C8BWxd8FLNiXjgO6?id=83013&db=object&view=detail
	Catalogue reference of an oral history from the sound archive on the
cessation of the tot in the RNZN

However if the point of the research is to find out why and when rum
(or any other alcohol) was issued, other word search term that may be
useful, try: "Tot" or "The Tot" and "Splice the mainbrace".

As a rough guide, in low tech vessels where due to dietary
deficiencies can occur due to poor food storage preserved foods, e.g.
in alcohol, will be used to maintain general health. Also the need to
maintain good order and discipline can be assisted with the use of a
controlled amount of a relaxant. On old terra, so the solomani tell
us, the tradition of issuing rum was an aide to keeping the crews of
sailing ships happy.

RFields
xxxxxx@actrix.co.nz
New Zealand, a small group of islands south west of California