﻿162 PEOF. T. G. BOIfNEY Oi!7 ANTIGOBITE [May I908, 



added ' Antigorite, Autigorio Valley.' (4) A thin polished slice, 

 resembling the last in translucency and colour (2^ by 2^ inches), 

 probably acquired before 1837 : registered by T. Davies as 

 ' Antigorite, Antigorio Valley.' (5) A box, with a lid, made of thin 

 polished slabs cemented together, 3fxl|xl^ inches; material 

 similar to the last two : this specimen has the same history as No. 4. 

 (6 & 7) Two paper-knives, mounted in wooden handles, material 

 similar to that of other polished specimens ; entered, under date 

 1831, as ' noble serpentine,' with the remark ' This substance 

 occurs in boulders on the shore of the Island of Ischia near K'aples.' 

 As I have never landed on Ischia, I cannot say more than that it 

 is one of the last places in which I should have expected to find 

 serpentine of this type. 



I regret to say that, when writing my note on the microscopic 

 section made in 1905,^ I supposed it to have been cut from ]S'o. 2, 

 to which the megascopic description applies. But I now find that 

 it represents Ko. 4, a small portion of which was ground down to 

 the requisite thinness. A second study of this slice has made me 

 less confident about the very few and very ill-preserved pyroxenes 

 being enstatite. I was led to this conclusion by observing traces 

 of a parallel cleavage (with straight extinction) in one or two 

 grains, but have found in specimens from the Saasthal (sliced since 

 those words were written) that occasionally the larger flakes of 

 antigorite (formed from grains of diallagitic augite somewhat bigger 

 than the rest) locally arrange themselves, side by side, so as to 

 present, with their straight extinction, a rather close resemblance to 

 a serpentinized enstatite.- In any case, whether these mottled rocks 

 were originally saxonites, Iherzolites, or augite-olivine peridotites, it 

 is evidentl}^ uncertain from what localities they were obtained. 



During our stay at Saas Grund last summer, we examined (as I 

 had done on previous occasions) the boulders of serpentine which 

 abound in the moraines of the Pee Glacier and o^i the bed of the 

 main valley between that village and the Mattmark Inn.^ I^ear the 

 latter they are exceptionally numerous in two places : one, just at 

 the lower end of the Mattmark See, where the path crosses a slope of 

 broken rock,mostly a fissileantigorite-serpentine, which veryprobably 

 formed part of the right moraine of the AUalin Glacier, when the ice 

 extended across the river"* ; the other, a short distance above the inn, 

 where the gigantic ' Blauenstein,' ^ with its two associates, one of 



^ Quart. Jouru. Geol. Soc. toI. Ixi, p. 700. 



* The structure of one grain, I may add, rather resembles that of olivine,, 

 though the strings are not marked out by iron-oxide. 



•^ See the paper bv Miss Raisin and myself in this Journal, vol. Ixi (1905) 

 pp. 707-709. 



4 As it did in 1860. 



' For a figure, see E. Whymper, 'A Guide to Zermatt & the Matterhorn' 

 7th ed. (190o) p. 189 ; J. de Charpentier (' Essai sur les Glaciers' 1841, p. 252) 

 states that in 1821 old men vrere still alive, who had heard their fathers say- 

 that they had seen it ' sur le dos du glacier,' As the size has been variouslj 

 stated, I may say that I measured it roughly in 1891, and found the length 

 to be 58 feet, the breadth 60 feet, and estimated the height as about equal to 

 the length. 



