If we want to find a stock that could multiply over the long term, what are the underlying trends we should look for? Firstly, we'll want to see a proven return on capital employed (ROCE) that is increasing, and secondly, an expanding base of capital employed. Put simply, these types of businesses are compounding machines, meaning they are continually reinvesting their earnings at ever-higher rates of return. Having said that, from a first glance at Sensient Technologies ( NYSE:SXT ) we aren't jumping out of our chairs at how returns are trending, but let's have a deeper look.