Mr. Hutton's Notes on the New Red Sandstone of Durham. 4-11 



ever did not occur, though both were decomposed together on 

 the sand heat. 



If the black precipitate be dissolved in nitric acid, nitrate of 

 silver does not indicate the presence of any muriatic acid; in- 

 deed whether the oxide was yellow or black, there was no 

 material difference in the quantity of chloride of silver yielded 

 by the decomposition of the submuriates : nor was there any 

 greater variation, than usually occurs in the results of ex- 

 periments, between the proportions of yellow or black oxide, 

 procured from equal portions of the submuriate. 



When the black oxide is dissolved in muriatic acid, water 

 occasions a precipitation of submuriate of the usual whiteness; 

 a portion of the black oxide heated to redness on a piece of 

 platina lost neither weight nor colour, but by melting it be- 

 came yellow ; and the last-mentioned circumstance is the only 

 one which affords even a guess as to the cause of the varia- 

 tions of colour, and that is the state of aggregation of the par- 

 ticles : but why it should not occasionally occur with the sub- 

 nitrate does not easily admit of explanation ; and it is, per- 

 haps, still more difficult to account for the uncertainty which 

 attends the results of different portions of submuriate, ob- 

 tained from one mass of bismuth. 



LXIII. Notes on the New Red Sandstone of the County of Dur- 

 ham, below the Magnesian Limesto?ie. By Wm. Hutton, 

 Esq. F.G.S. 



[Concluded from p. 354.] 



A T the south point of CullercoatsHaven, the great, or ninety- 

 "*•*- fathom dyke, as it is called, again brings down the mag- 

 nesian limestone and the yellow sand. The dyke may be seen 

 in the cliff, near the south point of the haven, where a coal sand- 

 stone and a bed of shale form its high or southern cheek, and 

 the yellow sand (here a soft sandstone) the northern. The 

 dyke hades, or underlies about 38° to the north, and its di- 

 rection is N. 87° W. Its course towards the sea may be traced 

 without difficulty, at low water, for a considerable distance 

 eastward, the well-known sandstone rock, called the " Bear's 

 Back," forming its southern side, and the yellow sand having 

 many thin beds of magnesian limestone alternating with it, 

 the northern. These alternating beds of limestone and sand 

 show marks of considerable mechanical force, being bent and 

 contorted near the edge of the dyke. Within the bay a bed 

 of shale is exposed to view, which here forms the southern 

 cheek of the dyke, in consequence of the action of the sea 



3 G 2 having 



