Chap. 24.] THE MAECIAN WATEE3. 487 



it has been boiled ; as also, that water when it has once been 

 heated, will become more intensely 15 cold than before a most 

 ingenious discovery. 16 The best corrective of unwholesome 

 water is to boil it down to one half. Cold water, taken inter- 

 nally, arrests hemorrhage. By keeping cold water in his 

 mouth, a person may render himself proof against the intense 

 heat of the bath. Many a person knows by his own every-day 

 experience, that water which is the coldest to drink is not of 

 necessity the coldest to the touch, this delightful property being 

 subject to considerable fluctuations. 17 



CHAP. 24. THE MAKCIAN WATEES. 



The most celebrated water throughout the whole world, and 

 the one to which our city gives the palm for coolness and salu- 

 brity, is that of the Marcian 18 Spring, accorded to Eome among 

 the other bounties of the gods : the name formerly given to 

 the stream was the " Aufeian," the spring itself being known 

 as " Pitonia." It rises 19 at the extremity of the mountains of 

 the Peligni, passes through the territory of the Marsi and through 

 Lake Fucinus, and then, without deviating, makes directly for 

 Rome : shortly after this, it loses itself in certain caverns, and 

 only reappears in the territory of Tibur, from which it is 

 brought to the City by an arched aqueduct nine miles in 

 length. Ancus Marcius, one of the Roman kings, was the 

 first 20 who thought of introducing this water into the City. 

 At a later period, the works were repaired by Quintus Mar- 

 cius Rex; and, more recently, in his praetorship, by M. 

 Agrippa. 21 



15 " Magis refrigerari." The experiments made by Mariotte, Perrault, 

 the Academy del Cimento, Mariana, and others, showed no perceptible differ- 

 ence in the time of freezing, between boiled and unboiled water ; but the 

 former produced ice harder and clearer, the latter ice more full of blisters. 

 In later times, Dr. Black, of Edinburgh, has from his experiments asserted 

 the contrary. " Boiled water," he says, " becomes ice sooner than unboiled, 

 if the latter be left at perfect rest." Beckmann's Hist. Inv. Vol. II. p. 145. 

 Jlohn's Ed. 16 " Subtilissimo invento." 



17 Or perhaps, as we say, " to the touch, and vice versa." The original 

 is " Alternante hoc bono." 



18 A considerable number of its arches are yet standing, and it still in 

 part supplies Rome with water. 



19 At Sublaqueum, now Subiaco. 



20 Primus auspicatus est." In obedience to the "auspices," probably. 



21 In A.U.C. 720. See B. xxxvi. c. 24. 



