lignite is probably nearer the truth. It is not improbable that spinos and the combustible "stones" found at Bina were merely varieties of the same mineral substance, different perhaps in respect to asphalt content, or possibly only in superficial appearance. That the ancients confused the various sorts of solid natural bitumens is fairly certain; even in modern times their classification has been a difficult problem.
The origin of the word spinos is obscure, and even the quantity of the first vowel is uncertain. It seems better to write σπίνος in the text, following Bekker in his edition of Aristotle, rather than σπίνος, which Wimmer prefers.
13. in mines. The actual reading of the manuscripts is iv τοις μβτάλλοις ("in the mines"), but Wimmer changed this to τοΐς (αυτοΐς) μβτάλλοις ("in the same mines"), meaning the mine at Bina mentioned in section 12. This emendation is supported by the passage in De Mirabilibus Auscultationibus which states that spinos was found in mines in a certain part of Thrace, by the fact that Bina was located in Thrace, and by the apparent similarity of spinos and the "stones" found at Bina. Nevertheless, it by no means follows that spinos was mined at Bina, and Wimmer's emendation has not been adopted.
13. // this is cut up and the pieces are piled in a heap, it burns when exposed to the sun, and it does this all the more if it is moistened and sprin\led with water. This statement probably describes the spontaneous combustion of a pile of bituminous material. Dry piles of such materials often ignite spontaneously under the proper conditions, as has been observed repeatedly with unventilated piles of ordinary coal. The last part of this statement, which is probably based on uncritical observation, describes the effect of throwing water on a pile of smoldering bituminous material. The clouds of smoke and steam are regarded as a sign of increased combustion. All the other ancient writers who describe the Thracian stone, some of whom certainly made use of this passage in Theophrastus, entirely misunderstood the reasons for its combustion, as is evident from their
