Geological Society, 317 



large square building represented in that ancient map, opposite to the 

 word Oplonti, indicates in other places a thermal spring, which the 

 recent excavations made in this spot prove to have existed there in 

 the time of the Romans. The catastrophe which overwhelmed the 

 cypress and fir, above alluded to, Dr. Daubeny conceives happened 

 prior to 572, because near Bosce-tre-case, about two miles to the 

 north of Torre del Annunziata, and on the slope of Vesuvius, was 

 lately discovered, a few feet below the surface, a bag of Roman gold 

 coins, evidently almost fresh from the mint, and bearing that date; 

 while he conceives that it may have been effected by the great erup- 

 tion of 472. Considering, however, that the buildings underneath 

 must have been overwhelmed by some eruption antecedent to that 

 which covered the trees (these latter appearing to have grown in 

 the very materials which enveloped the former), he is disposed to 

 assign the formation of the beds constituting the lower part of the 

 cliff to the eruption of 79 ; but he adds, it is remarkable that an event 

 which covered the neighbourhood of Torre del Annunziata to the 

 depth of more than 30 feet, should not have added sensibly to the 

 accumulation of volcanic materials over Pompeii. 



The spring of Torre del Annunziata possesses a temperature of 

 about 87° of Fahrenheit, and, according to the analysis of Professor 

 Ricci of Naples, abounds chiefly in the bicarbonates of soda, mag- 

 nesia, potass, and lime, with sulphate and muriate of potass, muriate 

 of soda, and muriate of magnesia. The quantity of carbonic acid gas 

 discharged is so great as to maintain the water constantly in a 

 violent ebullition, and to render the air in the stone cylinder through 

 which it escapes unrespirable. The same gas also rises in bubbles 

 through the sea, near the spot ; and there are patches of land upon 

 the cliff, upon which, owing to the disengagement of this gas, no 

 plant can be made to grow. Dr. Daubeny then points out the pre- 

 sence of oxygen and nitrogen gas, not only in the spring of Torre 

 del Annunziata, but in those of St. Lucia in Naples, at the Lago di 

 Amsanti, the Agua Santa on Mount Vultur, and the Lago di Solfa- 

 tara near Tivoli ; the proportion of oxygen varying from 9 to 16 per 

 cent., and of nitrogen from 84 to 91. With reference to the origin 

 of the nitrogen gas of these and other springs, Dr. Daubeny states 

 that he is ready to admit the possibility that it may, in many instances, 

 be separated from the water, and not be derived from an independent 

 source. 



To those, however, who refuse to admit volcanic action to be a pro- 

 cess of oxygenation, he says, such a mode of explaining the emission 

 of nitrogen would seem to remove the difficulty only one step further, 

 since it still remains to be shown why spring water, which is in ge- 

 neral impregnated more fully with oxygen than nitrogen gas, should, 

 in these cases, disengage chiefly the latter. He also adds, that in 

 none of the warm springs in the neighbourhood of Naples does nitro- 

 gen appear to be evolved in any notable quantity; and that the warm 

 springs of Ischia are destitute of all gaseous impregnation : and in 

 conclusion, whilst admitting that the hot springs of Campania fur- 

 nish no positive confirmation of the connexion between volcanic pro- 



