280 PLINY'S NATURAL HTSTOET. [Book XXVIII. 



were at war at the time. The prayer used upon the occasion 

 of this ceremonial, and which is usually pronounced first by 

 the Master of the College of the Quindecimviri, 26 if read by a 

 person, must assuredly force him to admit the potency of 

 formulae ; when it is recollected that it has been proved to 

 be effectual by the experience of eight hundred and thirty 

 years. 



At the present day, too, it is a general belief, that our Yestal 

 virgins have the power, by uttering a certain prayer, to arrest 

 the flight of runaway slaves, and to rivet them to the spot, 

 provided they have not gone beyond the precincts of the 

 City. If then these opinions be once received as truth, and if it 

 be admitted that the gods do listen to certain prayers, or are 

 influenced by set forms of words, we are bound to conclude 

 in the affirmative upon the whole question. Our ancestors, 

 no doubt, always entertained such a belief, and have even 

 assured us, a thing by far the most difficult of all, that it is 

 possible by such means to bring down lightning from heaven, 

 as already 27 mentioned on a more appropriate occasion. 



CHAP. 4. THAT PRODIGIES AND PORTENTS MAY BE CONFIRMED, OR 



MADE OF NO EFFECT. 



L. Piso informs us, in the first Book of his Annals, that King 

 Tullus Hostilius, 28 while attempting, in accordance with the 

 books of Numa, to summon Jupiter from heaven by means of a 

 sacrifice similar to that employed by him, was struck by 

 lightning in consequence of his omission to follow certain 

 forms with due exactness. Many other authors, too, have 

 attested, that by the power of words a change has been 

 effected in destinies and portents of the greatest importance. 

 While they were digging on the Tarpeian Hill for the founda- 

 tions of a temple, a human head was found ; upon which de- 

 puties were sent to Olenus Calenus, the most celebrated 

 diviner of Etruria. He, foreseeing the glory and success which 



The immolation of the Gauls is supposed to have happened in the beginning 

 of the reign of Vespasian. 



2G Originally the " Decemviri Sacris Faciundis," whose number was in- 

 creased by Sylla to fifteen. They had the management of the Games of 

 Apollo, and the Secular Games. 



27 In B. ii. c. 54. 



23 It has been suggested that Tullus Hostilius was acquainted with some 

 of the secrets of electricity, and that he met his death while trying ex- 

 periments with a lightning conductor. See B. ii. c. 54, 



