404 



CALCABEOUS PRECIPITATES. 



[Ch. XYII. 



But these 



through any number of successive envelopes, 

 nlsef can "never be perfect spheres, although they often 



v cm ob when a tr anver se section is made 111 any lme not 



72 dhecti of the point of attaint. The» are, 



ndeed, occasionally seen small oolitic and pisolihc grams, 

 of which the form is glohnlar , for the nnc ens, havmg been 



motion 



matter 



same maimer 



steam 



of enveloping crusts of 



matter 



series 01 enveiupnig ^ - . 



n phate of lime , so that a concretionary nodnle » formed, 

 "Irvine a nearly glohnlar shape, when increased to a mass 



preserving a nearly 



ameter 



In these, as in many travertins, 



several incurs aii ^"*~ - 



there is often a combination of the concent™ and 



r 



structure. 



Campagna di Roma. 



ome 



partTof To Tn cl ' States already referred to, has been at 



par^s 01 tuo ^nlpanio, eruDtions; 



some 



and the spi 



rmer period the site of numerous volcanic eruptions j 

 , springs are still copiously impregnated wnh hme, 



SS ^Xa^lphuretted hyirogem A hot spring 



discovered about 1827, near Civita ^ >2ii&Z 

 Eiccioli, which deposits alternate beds of a '7^ * 

 vertin, and a white granular rock, not ^^^* 

 Hand specimen, either in grain, colour,^ = f ^ 

 statuary marble. 



There is a passage 



between this and 



oXa7y =m The mass accnmnlated near the spring 

 is in some places about six feet thick. 



U 0/ ft. 8olfatar a .-In the Campagna between B-» 

 and Tivoii, is the Lake of the Solfatara, called also lago * 

 Zolfo (lacns albula), into which flows corrtrnuaUy » *»- 



from 



it. 



I water irom a »^ 11Ci «— ~» . -j . aS , 



The water is a saturated solution of carbonic acid ^ 



om it in such quantities m some 



snrface, that it has the appearance o^*^ . 



rf 



Hiu x . n 



■ that the water taken from the most tranqnfl part 



tion. 



TjlUiL Lilt? VVcLUCl ucuj^** , -, 



lake, even after being agitated and exposed to t he ^ ^ 

 tained in solution more than its own volume of car 



con- 

 id 







I 





i 



/ 



I 



C* 



& 



V 



i 



' 



its 



hi 



an 



dt 



bank 



confe 



same 

 cryst 



depoi 

 likevs 



fflier 



conti 

 force 



of HI 

 Tl: 



mass 

 and: 



with 



the s 



uppe 



km 



conti 



infet 

 coloi 



sitio: 



T] 

 nine 



land 

 posi 



ree e 



mile 



the 



mos 

 of t 



Mi 



tli 



e 



e 

 1 



