In our endeavour to find a modern way of overcoming the conception of matter developed and held by science in the age of the onlooker-consciousness, we shall be helped by noticing how this conception first arose historically. Of momentous significance in this respect is the discovery of the gaseous state of matter by the Flemish physician and experimenter, Joh. Baptist van Helmont (1577-1644). The fact that the existence of this state of ponderable matter was quite unknown up to such a relatively recent date has been completely forgotten to-day. Moreover, it is so remote from current notions that anyone who now calls attention to van Helmont's discovery is quite likely to be met with incredulity. As a result, there is no account of the event that puts it in its true setting. In what follows pains are taken to present the facts in the form in which one comes to know them through van Helmont's own account, given in his Ortus Medicinae.