Browning's poetry, that doubt is a condition of the vitality of faith." 17. Snakestone: a name given to any substance used as a remedy for snake-bites; for example, some are of chalk, some of animal charcoal, and some of vegetable substances. 28. Vespasian: Nero's general who marched against Palestine in 66, and was succeeded in the command, when he was proclaimed Emperor (70-79), by his son, Titus. 29. Black lynx: the Syrian lynx is distinguished by black ears. 43. Tertians: fevers, recurring every third day; hence the name. 44. Falling-sickness: epilepsy. Caesar's disease ("Julius Caesar," I. 2, 258). 45. There's a spider here: "The habits of the aranead here described point very clearly to some one of the Wandering group, which stalk their prey in the open field or in divers lurking-places, and are distinguished by this habit from the other great group, known as the Sedentary spiders, because they sit or hang upon their webs and capture their prey by means of silken snares. The next line is not determinative of the species, for there is a great number of spiders any one of which might be described as 'Sprinkled with mottles on an ash-gray back.' We have a little Saltigrade or Jumping spider, known as the Zebra spider (Epiblemum scenicum), which is found in Europe, and I believe also in Syria. One often sees this species and its congeners upon the ledges of rocks, the edges of tombstones, the walls of buildings, and like situations, hunting their prey, which they secure by jumping upon it. So common is the Zebra spider, that I might think that Browning referred to it, if I were not in doubt whether he would express the stripes of white upon its ash-gray abdomen by the word 'mottles.' However, there arc other spiders belonging to the same tribe (Saltigrades) that really are mottled. There are also spiders known as the Lycosids or Wolf spiders or Ground spiders, which are often of an ash-gray color, and marked with little whitish spots after the manner of Browning's Syrian species. Perhaps the poet had one of these in mind, at least he accurately describes their manner of seeking prey. The next line is an interrupted one, 'Take five and drop them. . . .' Take five what? Five of these ash-gray mottled spiders? Certainly. But what can be meant by the expression 'drop them'? This opens up to us a strange chapter in human superstition. It was long a prevalent idea that the spider in various forms possessed some occult power of healing, and men administered it internally or applied it externally as a cure for many diseases.