Dear Ian,
Thank you for the link! I have been reading it and looking up Henry Piddington esq who sounds a fascinating gentleman in his own right, having been accredited with originating the term 'cyclone'! It may indeed give me more to go on at the BL. I had found other detailed articles on Saltpetre manufacture in other Asiatic Journals, but none of them gave the definitive statement that JS was employed by the company before he went out to India. He was obviously thought very highly of and beyond any ulterior motives in his research!
In reviewing all the info so far I noticed that on Catherine Mary's marriage certificate one of the witnesses was a James Bogie. He is quite possibly a friend of the groom but maybe an outside chance he was a family friend of JS and am looking into him, quite a distinctive name...
I have also emailed the Gunpowder Society history group who mentioned an original article they found by JS at the back of an old book. Unfortunately although they know of him and his work has been listed as important, they have no personal details.
Regards,
Maggie