In 1955 the Belgian physiologist Christian de Duve applied the techniques of ultracentrification and electron microscopy to discover a group of new membrane bound organelles within animal cells. These structures were full of enzymes capable of breaking down a wide variety of biological polymers and the organelles became known as lysosomes. In subsequent years it slowly became apparent that these lysosomes were associated with a whole group of cellular storage diseases. It was also discovered that calcium was involved with lysosomes and acted as a component in the cellular signalling and cell survival systems. They were a totally unsuspected aspect of inorganic biochemistry.