In 1843, when the luminosity of plants was recorded in the Proceedings of the British Association, Mr. Babington mentioned having seen in the south of England a peculiar bright appearance produced by the presence of the Schistostega pennata, a little moss which inhabited caverns and dark places: but this was objected to on the ground that the plant reflected light, and did not give it off in phosphorescence.[4]
When lighted on, it has the appearance of a handful of emeralds or aqua marine thrown into a dark hole, and is frequently associated with the bright green liverwort. Parfitt, in his Moss Flora of Devon, gives it as osmundacea, not as pennata. It was first discovered in Britain by a Mr. Newberry, on the road from Zeal to South Tawton; it is, however, to be found in a good many places, as Hound Tor, Widdecombe, Leather Tor, and in the Swincombe valley, also in a cave under Lynx Tor. If found, please to leave alone. Gathered it is invisible; the hand or knife brings away only mud.
But what all are welcome to go after is that which is abundant on every moorside—but nowhere finer than on such as have not been subjected to periodical "swaling" or burning. I refer to the whortleberry. This delicious fruit, eaten with Devonshire cream, is indeed a delicacy. A gentleman from London was visiting me one day. As he was fond of good things, I gave him whortleberry and cream. He ate it in dead silence, then leaned back in his chair, looked at me with eyes full of feeling, and said, "I am thankful that I have lived to this day."
The whortleberry is a good deal used in the south of France for the adulteration and colouring of claret, whole truck-loads being imported from Germany.
There is an interesting usage in my parish, and I presume the same exists in others. On one day in summer, when the "whorts" are ripe, the mothers unite to hire waggons of the farmers, or borrow them, and go forth with their little ones to the moor. They spend the day gathering the berries, and light their fires, form their camp, and have their meals together, returning late in the evening, very sunburnt, with very purple mouths, very tired maybe, but vastly happy, and with sufficient fruit to sell to pay all expenses and leave something over.
If the reader would know what minerals are found on Dartmoor he must go elsewhere.
I have a list before me that begins thus: "Allophane, actinolite, achroite, andalusite, apatite"—but I can copy out no more. I have often found appetite on Dartmoor, but have not the slightest suspicion as to what is apatite. The list winds up with wolfram, about which I can say something. Wolfram is a mineral very generally found along with tin, and that is just the "cussedness" of it, for it spoils tin.
When tin ore is melted at a good peat fire, out runs a silver streak of metal. This is brittle as glass, because of the wolfram in it. To get rid of the wolfram the whole has to be roasted, and the operation is delicate, and must have bothered our forefathers considerably. By means of this second process the wolfram, or tungsten as it is also called, is got rid of.
Now, it is a curious fact that the tin of Dartmoor is of extraordinary purity; it has little or none of this abominable wolfram associated with it, so that it is by no means improbable that the value of tin as a metal was discovered on Dartmoor, or in some as yet unknown region where it is equally unalloyed.
In Cornwall all the tin is mixed with tungsten. Now this material has been hitherto regarded as worthless; it has been sworn at by successive generations of miners since mining first began. But all at once it has leaped into importance, for it has been discovered to possess a remarkable property of hardening iron, and is now largely employed for armour-plated vessels. From being worth nothing it has risen to a rapidly rising value, as we are becoming aware that we shall have to present impenetrable sides to our Continental neighbours.