But, what people didn’t realize was that celluloid was manufactured using a compound called cellulose nitrate.

但是，人们没有意识到赛璐珞是用一种叫做硝酸纤维素的化合物制造的。

And when you expose cellulose, like in wood pulp or cotton, to nitric acid, it forms cellulose nitrate -- which is highly flammable.

当你将纤维素（ 如木浆或棉花）暴露在硝酸中时， 它会形成高度易燃的硝酸纤维素。