Nobel cut his finger on a piece of glass one day at work and subsequently applied collodion in order to form a protective layer over the wound (similar in principle to liquid bandage). Nobel was kept up at night by the pain in his finger, so he started to think about a problem he was having back at work: Nobel was trying to create a powerful explosive using nitrocellulose and nitroglycerine, but the two would not combine. Roberts reports that Nobel then realized that collodion (which he was using to dress his wound) could allow the two substances to combine, which led to the invention of blasting gelatin (as powerful as dynamite but much safer to handle).[1]