Dr. A. Wilmore—Uralite and other Amphiboles. 361 
chloride. The felspars of this Oodegaarden rock evidently became 
saturated along their solution-planes with sodium chloride in solution, 
and the effect of the internal stresses in the rock masses was to “‘ bring 
about those chemical reactions by which the felspar-molecules were 
broken up and their materials united with the sodium chloride to form 
scapolite’’. 
The pyroxene has undergone a precisely parallel series of changes. 
The original pyroxene was very nearly colourless, probably an enstatite. 
It was converted into a schillerized ‘ bronzite’ by enclosures parallel 
to a pinacoid. This pale-coloured bronzite is, in places, found to be 
acquiring the characteristic colour, pleochroism, and absorption of 
brown hornblende. 
‘The last stage in the change of the Oodegaarden pyroxene is seen 
in certain crystals which; around their edges and in certain patches 
in the middle, exhibit the full pleochroism, the absorption, and the 
characteristic cleavage of hornblende. This is often accompanied by 
‘oeranulation’ of the broad plates of the original pyroxene. The 
original rock appears to have a perfectly granitic structure, but the 
derived hornblende-scapolite rock has a granulitic structure. 
The effects produced are the results— 
(1) of chemical action resulting from statical pressure (schillerization) ; 
(2) of changes induced by the internal stresses set up in a rock during its 
deformation in the act of flowing (dynamo-metamorphism). 
Professor Judd described the change from pyroxenes to hornblende 
as a ‘paramorphic’ one, but that from felspar to scapolite as a 
‘pseudomorphic’ one. 
Two important papers of a different type by Professor Judd may 
now be noticed. ‘The first of these is his well-known paper on the 
Peridotites of Scotland. In this paper he gave a classification of 
pyroxenes with ‘ Schiller’ varieties, which is here reproduced. 
Unaltered forms. ‘ Schiller’ varieties. More altered forms. 
‘ Enstatite proper Diaclastite ? 
Enstatites Proto-bronzite Bronzite Tale? 
(Rhombic) Proto-hypersthene Hypersthene } j 
Amblystegite Hypersthene Bastite 
Tere Diopsides Diallage and Green diallage 
ugites ase Baath quia 
(Monoclinic) ugite proper seudo- and 
Hedenbergite hypersthene Smaragdite 
An interesting alteration series is given on p. 3881 of this paper— 
Smaragdite 
Actinolite and 
Augite, diallage, green diallage 
similar hornblendes. 
On p. 386 he distinguished ‘weathering’ changes which produce 
kaolinization, uralitization, serpentinization from the changes which 
produce schillerization. The latter is deep-seated, the others are not 
deep-seated. 
The next paper of Professor Judd deals with the Tertiary Gabbros 
in Western Scotland and Ireland.? In it he emphasized most strongly 
1 © Qn the Tertiary and older Peridotites of Scotland’’: Quart. Journ. Geol. Soc., 
1885, vol. xli, pp. 354-418, pls. x—xiii. 
* Quart. Journ. Geol. Soc., vol. xlii, p. 49 et seq. 
