230 REPORT OF NATIONAL MUSEUM, 1904. 



characters and conduct before the blowpipe, and their place of occur- 

 rence. Perhaps no better means of showing the condition of the 

 science at that time can he found than by reproducing here a page of 

 the original descriptive matter under Class I. Order II. 



Species YIJ — Wacke. 



Wacke, Cleaveland, p. 287. Wacce, Jameson, vol. 1, p. .'!7f>. Wacken, Kirwxn, 

 vol. 1, p. 223. Wakke, Aikin, p. 254. 



External characters. 



Its colours arc grey and purple. Of grey, it occurs blackish grey and greenish 

 grey; of purple, lavender purple. The colours vary much in their intensity. 



It is dull. 



It is amorphous ami cellular. 



It exhales a strong argillaceous odour when breathed upon. 



It adheres to the tongue. 



Its streak is greyish white, with a reddish purple tinge in some parts, and is dull. 



It is moderately hard, passing to soft. 



The fracture is from fine grained uneven to earthy; some specimens show a slightly 

 slaty structure. 



It is brittle. 



It is easily frangible. 



The fragments are indeterminately angular and not particularly sharp edged. 



Its specifick gravity is about 2.88. 



( 'hymical characters. 



Before the blowpipe it melts into an opaque, semi-vitreons mass which appears 

 porous when broken. 



Geological situation and localities. 



It occurs in beds in Petrosilex at Milton, and forms the basis of Amygdaloid at 

 Brighton, Ilingham, Newton, Ac, and it is found also in rounded fragments at 

 Xeeilham, Newton, Brighton, &c. 



Remarks. 



This mineral sometimes much resembles ferruginous clay, and is intermediate 

 between ( 'lay and Basalt. It is very liable to decomposition, and when it forms the 

 basis of Amygdaloid, by undergoing tins change, it leaves the imbedded minerals 

 projecting, or they fall out and leave the Wacke cellular. " 



In 1818 there was published by Kirk and Mercein in New York 



Robert Jameson's translation of Cuvier's celebrated essay on the 



Theory of the Earth, and with it S. L. Mitchill's Observations on the 



Geology of North America. 6 It is the Observations 



Mitchillon the s * . , , . 



<jeoio K y of North alone that need now receive our attention, and this 



America, 1818. . . . ., , 



with particular reference only to what is stud regard- 

 ing the origin of the drift. Mitchill was one of the most prominent 



"This work was the subject of a scathing review in the Analectic Magazine, XIII, 

 1819, where the writers were accused of having borrowed at least three-fourths of 

 their material "for the mere purpose of eking out the matter to the proper size of a 

 justum volumen — of borrowing the most elementary ideas of the most common authors." 



* * "A student who has read either Cleaveland, Jameson, or Aikin, will find not 

 a sentence that is new in at least nine-tenths of the book; which is in fact a disgrace- 

 ful example of literary book-making, as it respects both the matter and the manner." 



''There was manifested, particularly by the publishing houses of Philadelphia, an 



