Motrix

[jbor at bigpond.com]

On 09/01/2006:

> Pynchon uses the phrase "the Motrix of honest Mirth."  I
> couldn't find Motrix in my dictionary.

It's from Latin but was in common use in English at the time (words 
like motor and motive derive from the same Latin root). Impulse, cause, 
spirit -- something like that.

The context makes it pretty easy to work out what's happening: Dixon's 
laugh is fake, "the laugh of a hired Foil". But his self-consciousness 
enriches the characterisation, and highlights how awkward this first 
meeting is. Having snapped back and thus demonstrated his annoyance at 
Mason mocking his accent and heritage, Dixon again pretends to laugh to 
interrupt Mason's apology.

http://www.ancts.org/resources/chadwick/m.php

best