Just been reading a fairly interesting book on a deceased soldier from 3rd Worcesters in 1916. One of the accounts written up describes fumite bombs as a smoke and flame generating bomb made of white phos, wax and petrol, sounds interesting so I fumite bombs - Google Search. Interestingly the Fumite bomb - Great War Forum were adamant they were smoke only and can still be bought. I suspect the ones on sale to the public were basically mole fumigators/insect killers and I think I will have to get some and see how they work. I think as well that I will have to make one but what I wonder can I use instead of WP, Magnesium powder perhaps? The reason I think that the military issue recipe was designed to burn is based on the officers diary quoted in the book where the fumite bombs ruin the German dugouts by burning the timbers and collapsing them and also the smoke plume gives an aiming marker for the Huns Gunners. The Book is Bringing Uncle Albert Home by David P Whithorn.