Charles Godfrey Leland, Etruscan Roman Remains in Popular Tradition p. 265-66
This is an extremely curious and ancient formula of declaring that whatever one does is not to stop at a certain point. By means of it almost any action is turned into magic. Thus to find and pick up anything, at once converts it into a fetish, or insures that all will go well with it if we say when taking it: “I do not pick up”,–naming the object–“I pick up good luck, which may never abandon me!” It is an incantation of universal application, enabling one to secure a wish out of every chance occurrence.
The spider is also used in divination. I find the following in a popular chapbook:–
Il Ragno Industrioso. In the Book of Dreams, and in the works of the famous cabalists Rutilio Benicosa, Casamia, l’Indovino, Il Palmaverde, Nostradamus, and the ancient Sybils or Haruspices, we often find methods of divining the secret of getting numbers by the lottery. Among the many extraordinary experiments made, the most singular is that by means of the spider.
Take one of these insects-let it be very large-and put it, without hurting it, in a little box,on the bottom of which are many small pieces of paper, numbered from one to ninety. Cover it with a transparent veil, and give the spider time to weave a web.
Naturally the insect in going here and there will turn up certain numbers. These must be noted. Do this three times, and then let the spider go. Many have won lucky numbers in the lottery by means of this experiment.
It may be observed that it is necessary to the success of this sortilege that we let the spider go. So in several of the charms Of MARCELLUS, the animal used in such spells must be dismissed in safety–Ecce dimitto te vivam!
The spider, it may be observed, can also be used for other divination as well as for lucky numbers in the lottery. Thus, if you write “Yes” or “No,” she will turn up for you an affirmative or negative for any question, or select the names of friends or enemies, or pick out lucky days.