(2i88) 
^M/ of Sea- fifties, the lhapes of ftfr^/^/and Plants, &c. 
From the Change of xhtScite of Beds he givech an Ac- 
count; I. Of the Principal Origin of Mountains^ Hillocks 
tLXxd Valleys^ atid their various Conftitution, Matter, Shape, 
2» Of the Paflages for ^/n>7g/ and r/^/W/ rufliing out 
of Mountains, foetid Exhalations, hot Ebullitions 5 asaUo 
of the Changes of Hot Springs into Cold^and the Turning 
of the Courle of Rivers another way; of Rivers,running 
in one place under ground , and rifing again in another ; 
of whole Countries being fwallow'd up with their Houfes 
and Trees 5 of great Lakes now appearing where Towns 
ftood formerly, ^c^ 3* Of the many kinds of variegated 
Stones J as aUo of the Receptacles of jlfirierals • where do 
occur very good Obfervations. 
In his difcourfe about Jugular Bodies^ he delivers many 
confiderablc things about the Production of Cbryjlals in the 
Cavities of Stones, about their firft Concretion between 
two Fluids,or between a Fluid and a Solid,or in a Fluid ; as 
alfo about the A/omn of the Chryltal in matter, whereby ic 
is dctermin'd to the Planes of the all-ready forra*d Chryftal; 
Concluding from his Obfervations, thatextream Cold is 
not the Efficient caufe of Chryftals 5 nor that 'tis the A(hes 
alone burnt by fire that turn into Glafs^ nor the force of 
the Fire alone that produceth Glafs ; and that 'tis not be- 
yond the power of Man, to difcovera produdlion of Glafs 
without the violence of Fire : Where, by the by , he intis 
mates what it is, whence depends the main caufe of the 
difference of Chryftal from Glafs 3 both as to Refra<ftioa 
and other Operations. 
From Chryftals he paffeth on to confider the Angular 
Bodies of Iron and Copper-^ and flieweth, how the produ- 
ction of them agreeth in fv>me things with that of Chry- 
ftals, and how it differs from them* 
Thence he goes on to Diamonds, and obferveth,how they 
alfo are produced in a Fluid mclofed in the Cavities of 
Stones, together with the variety of their Figure. Next, 
he difcourleth of Marcajttej^ and delivers alio feveral Ob« 
fcrvations 
