Things of real worth, such as the mental life of the ant or the crab, fill psychological and scientific literature; but such a thing as death, which … - Charles Webster Leadbeater

The first difficulty that faced us was the identification of the forms seen on focusing the sight on gases. We could only proceed tentatively. Thus, a very common form in the air had a sort of dumb-bell shape (see Plate I); we examined this, comparing our rough sketches, and counted its atoms; these, divided by 18—the number of ultimate atoms in hydrogen—gave us 23.22 as atomic weight, and this offered the presumption that it was sodium. We then took various substances—common salt, etc.—in which we knew sodium was present, and found the dumb-bell form in all. In other cases, we took small fragments of metals, as iron, tin, zinc, silver, gold; in others, again, pieces of ore, mineral waters, etc., etc.... In all, 57 chemical elements were examined, out of the 78 recognized by modern chemistry. In addition to these, we found 3 chemical waifs: an unrecognized stranger between hydrogen and helium which we named occultum, for purposes of reference, and 2 varieties of one element, which we named kalon and meta-kalon, between xenon and osmium... Thus we have tabulated in all 65 chemical elements, or chemical atoms, completing three of Sir William Crookes' lemniscates, sufficient for some amount of generalization. (Chapter III. The Later Researches)

It seems that in the Koran there is a wonderful narrative concerning a visit paid one morning by the prophet Mohammed to heaven, during which he saw many different regions there, had them all very fully explained to him, and also had numerous lengthy conferences with various angels; yet when he returned to his body, the bed from which he had risen was still warm, and he found that but a few seconds had passed — in fact, I believe the water had not yet all run out from a jug which he had accidentally overturned as he started on the expedition! Chapter 4

For the purpose of this treatise we may, perhaps, define it as the power to see what is hidden from ordinary physical sight. It will be as well to premise that it is very frequently (though by no means always) accompanied by what is called clairaudience, or the power to hear what would be inaudible to the ordinary physical ear; and we will for the nonce take our title as covering this faculty also, in order to avoid the clumsiness of perpetually using two long words where one will suffice.