I can see that for the last one, but what about the first five instances?
- B. Clay Shannon 

    On Saturday, July 13, 2019, 07:04:30 AM PDT, [log in to unmask] <[log in to unmask]> wrote:  
 
 It’s Listerine Clay. It was invented in the 19th century as an all-purpose antiseptic cleaner.
Alan K.

Sent from my iPhone

> On Jul 13, 2019, at 9:16 AM, Clay Shannon <[log in to unmask]> wrote:
> 
> I am fearlessly reading the stupendous "Mark Twain Day By Day," and in volume 2 of the digital edition, I note that it contains the assemblage of letters ("isterine") in multiple (6) places. My hunch is that this is a global search-and-replace gone wrong, but I haven't figured out just yet what the replaced word or fraction of a word originally was.
> Here are the occasions where it occurs:
> 0) saving it up, & isterine it, & making it last as long as possible
> 1) and I were isterine up and down the library 
> 2) Finally he said to Mamma in an isterine tone, 
> 3) recounted the isterine stories which each Knight 
> 4) He was such a isterine speaker 
> 5) Mch 16 Bottle isterine 1.00 Mch 17 Flax Seed .35 tot 1.35 
> 
> 
> Does anybody know what I should replace (in my mind) when I come across "isterine"? "Punch, Brother, Punch with Care" does not quite seem to fit...
> - B. Clay Shannon