420 



THE GEOLOGIST. 



the solution, and expose it either to the air or to the heat of an oven until the 

 water of crystallization has escaped ; then, this prepared chalk, when put into 

 boiling water will probably break up without greater force being employed than 

 a common painter's sash-tool will exert upon it. The fins particles should 

 then be washed away ; and the remainder will probably be found to consist of 

 Foramimfera, and should be mounted in Canada-balsam, to be seen properly." 



Some of the White Chalk of Yorkshire, however, reqmres to be sliced and 

 polished before it can be examined microscopically. It is very intractable, as 

 Mr. Norman, the weU known microscopical mechanist, found, though he suc- 

 ceeded in overcoming the difficulty and in preparing some very good slides. 



The lied Chalk from Elamborough, having been manipulated by Mr. Deane, 

 was examined by Messrs. W. K. Parker and T. E. Jones, and was found to 

 contain the io]iQvang Forammifera \ — Globigerina hulloides ; small, very com- 

 mon. Text'ularia ])ygmcea ; small, common. Rotalia ammonoides ; small, 

 rather common. Dentalina communis; small, rather common. Qristellaria 

 rotulata ; of middling size, rare. 



These gentlemen also inform me that the thin slices of the hard White 

 Chalk from Elamborough, when magnified fifty diameters, are seen ;to be ex- 

 ceedingly full of minute chambers, or cells, of Glohigerina and Dentalina ; the 

 former predominating. There are also a few Textularice, observable. The 

 chambers are generally separate ; but here and there characteristic groups of 

 them remain attached to each other. The general appearance is that of very 

 finely washed common chalk. 



These Foramimfera indicate a deep-sea-condition to have been that of the 

 Chalk-deposit, and such as that of the mid-Atlantic or the Indian Ocean, where 

 Glohigerina still abounds. 



Treated with acid, one of the specimens of the White Chalk exhibited evident 

 remains of organic matter, such as what may well be considered as disintegrated 

 dry sarcode of Foramimfera. It is chiefly globular; but some of it is 

 filamentous. 



Chemically examined, the Ked Chalk gives 70 per cent, of carbonate of lime; 

 the residue being quartz-grains and silicate of iron. Digested in very strong- 

 acid, about 4 per cent, of peroxide of iron is obtained. The White Chalk 

 leaves scarcely any residue when treated with muriatic acid. — Majoe-Gen. 

 Emmett, R.E., E.G.S. 



Clai-Slate and Geanite. — A correspondent in Halifax, Nova Scotia, 

 mentions the following interesting facts : — " This province has many points of 

 geological interest, which have been all ably dealt with by Dr. Dawson. In 

 tLe sQiall way, it is curious to observe the highly metamorphic condition of 

 ' clay-slate' when more or less acted on by granite. I have a beautiful speci- 

 men of granite containing two still well-laminated fragments of slate. Another, 

 in which the fragment seems turned into a granitoid stone ; and every stage of 

 the process is to be seen in all the chiselled blocks of ' ashlar' (granite) in the 

 various buildings hereabouts, a disfigurement to the white granite, it is true, 

 but very interesting to geological scrutiny. Also, this clay-slate has more 

 than a tendency, at times, to turn into mica-slate. Once I caught it in the 

 fact of looking very like rudimentary hornblende-slate. 



There is a large boulder of the metamorphic slate on the hill above here, 

 Avilli cfpial tendencies to weather in coats, as we so frequently see in granitic 

 elu'csowrings, basalt, trachytes, and I believe, all igneous rocks. 



Auollicr ]ioint is its extensive tendency to become wliite externally, as if it 

 AViTc frlspat hie." 



Iminsh, UoMis \\ l\i;()(i;\i()KE. — A IVagiiinit of a leg-bone of an Elcpliant, 

 Ihis (i)^ a biokc'ii horn-core of 1)08, and an antler of Ccrr/'n inter- 

 medium (r) have lately been met with near the New Garden, at Erogmorc, in a 



