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PKOF. T. G. BONNET OJS ANTIGORIIE 



[:y:ay 1908, 



Pennine chain, but from a short spur which runs out eastward 

 from the Portjen Grat. On the eastern side, the Yal Yigezzo and 

 perhaps the Isorno Valley are the only tributaries of any import- 

 ance — the mouth of the former being almost opposite to that of 

 the Val Bognanco. 



Under the circumstances, I thought that my best chance of running 

 the antigorite to ground was to go up the Yal Antigorio from Domo 

 d'Ossola, keeping a sharp look-out for serpentine either as an erratic 

 or in situ ; and, if no sign of it appeared, to examine the pebbles 

 in the bed, both of the Tosa and of its tributaries, since these 



ShetcJi-majp of the Val- Antigorio district. 



would show whether any important mass of that rock occurred 

 in the Yal Formazza or in the other valleys. The test, though 

 obviously imperfect, is a fairly safe one, unless the outcrop be quite 

 small. 



In applying it, I had the kind assistance of my friend, the Eev. 

 Edwin Hill, who about a fortnight before had joined me at Saas 

 Grund, and thus had become as familiar with antigorite-serpentines 

 as with those of the Lizard. A walk about Domo d'Ossola on the 

 evening of our arrival gave some hope of success, for among the 

 pebbles paving its streets serpentine of the Saasthal type is not 

 rare. Xext morning we drove up the Tosa Yalley to San Rocco, 



