More than 60 years ago I was told that the foaming agent in the fire trucks contained urea extracted from animal blood, hence the awful smell a few days later. The stuff had a very high nitrogen content, so Warrant Officer Gilliland at Binbrook seized the time-expired cans to sprinkle upon his rose beds. The results were magnificent but nobody dared go close enough to smell the luxuriant blooms.
Of course such smelly occasions and their gruesome background were of great appeal to small boys, especially as we were told the blood came from the pigs which we saw being slaughtered behind John Cook's butcher shop in the village. So maybe this particular child was having his leg pulled.
