10 Dr. Troost on Amber, ^c, 



the horizon is to be observed, and this seems owing, at the 

 spot examined, to a small undulation.f 



Below this, is a stratum of sand intermixed with pyrites, 

 in which are often found large nests of this mineral, 15 to 

 20 feet in square surface, and from one foot to one foot and 

 an half in thickness. The quantity of pyrites this bed pro- 

 duces is astonishing ; having cleared off its superincumbent 

 >;trata of sand and lignite, (a surface of perhaps 1700 square 

 feet,) it gave roe, excluding the pyrites, which were broken 

 up into small pieces, upwards of twenty-five tons. This 

 stratum is here and there entirely wanting, its place being 

 then occupied by shaly clay. 



There follows a bed of earthy hgnite. from 5 to 12 feet 

 in thickness, embracing a great abundance of pyritous wood, 

 intermixed with large fragments, thirty and more feet long, 

 of bituminous wood. This bed is intersected by streaks 

 and nests of a grey clay and a fine grained earthy lignite, 

 bearing much resemblance to the amber of Cologne. There 

 occur in this, pebbles of greasy quartz, and in one instance, 

 a small crystal of Disthene was found, two substances which 

 occur in abundance in the primitive rocks, fifteen or twenty 

 miles distance from here, principally near Baltimore. 



In this stratum of lignite, was found a substance which T 

 at first sight mistook for a fruit, endeavouring to find its 

 analogy among the palm fruits. The error soon, however, 

 became manifest from the observation, that what had been 

 taken for the stem of the fruit, was not implanted in it, but 

 traversed its centre, and sometimes perforated its sides — 

 tvvo circumstances bearing no analogy to the stem of fruits. 

 The substance was therefore subjected to a more attentive 

 investigation, the result of which led to the belief, that it 

 was an animal product of a very curious nature, and that it 

 could be nothing else but a kind of comb or nidus made by 

 some insects around the twigs and extremities of the succu- 

 lent branches of a tree. 



The size of these nests is from one to three inches m 

 length, their diameters varying in proportion — for instance, 

 if the nest have three inches in length, its diameter will 

 Imve commonly one inch ; if one inch in length, its diame- 

 ter will have half an inc;]. Their shape is irregular, their 



* rice Nole second, at the end of tbe .Menmii' 



