Not the usual sort of thing I buy, but it looked intriguing and as I didn't know anything about these, it has been interesting so far finding out. I think it is a "valve codd" (according to Miller's Bottles & Pot Lids - A Collector's Guide
p.35). I've managed to take a pic. of the inside showing its round marble and rubber washer which seems fixed to the base. Its marked J.H.FERGUSON 38 KINGS GARDENS PLYMOUTH / REGISTERED TRADEMARK / CANNINGTON SHAW 7 CO. MAKERS ST. HELENS, and has A4 on the base.
This excellent link http://www.plymouthdata.info/Business%20Houses-Furguson%20JH.htmshow
states that J.H. Ferguson moved his mineral water business to Kings Gardens in 1889 following expansion. Cannington Shaw bottle makers operated from 1872-1916 (Glass fact file a-z
. Ivo Haanstra), so the bottle must date some time from 1889 to 1916.
The patchy iridescence puzzled me, but it would seem that this is the result of it being buried, where it has been affected by the minerals in the ground, so at some point it has been dug up. I'm leaving it as it is - uncleaned.