Complex sentence: Having taken up the idea of quantitative mouth blowpipe assaying, which was then almost unknown, he succeeded in devising dependable methods for all the ordinary useful metals; in particular his modes of assaying for nickel and cobalt quickly found favour with metallurgists.
Split into simpler sentences: Having taken up the idea of quantitative mouth blowpipe assaying, which was then almost unknown, he succeeded in devising dependable methods for all the ordinary useful metals. In particular his modes of assaying for nickel and cobalt quickly found favour with metallurgists.