May 2, 1 8 72 J 



NATURE 



II 



gard to this last rare mineral substance, to which Fergus- 

 son never alludes beyond mentioning its existence, I 

 pointed out some time since that seventy-five per cent. 

 of the celts found in the sepulchral dolmen-mounds of 

 Brittany were composed of this material.* Can Mr. p'er- 

 gusson inform us how he accounts for the presence of 

 this substance, as well as the significance of its pre- 

 dominance in association with sepulture? It may be noted 

 that all the fibrolite celts are small and nearly perfect, 

 with sharp edges, and show no signs of use ; whilst the 

 diorite and other celts of a larger type show evident signs 

 of use and axe 3X\ puijiosi'ly broken before deposition in 

 the dolmen. 



VI. P. 356. More strictly the jade and turquoise should 

 be termed jadJi/e and caUai's, respectively. Mr. Fer- 

 gusson is right in quoting '' jade " and '■ turquoise " if he 

 goes by M. Rent? Galles' account, and I quoted the same 

 materials myself in an article on Dolmen Mounds in the 

 Quarterly Jouriuil of Science last January ; but these 



Fig. 3. — Le Grand Menhtr, Restored bv Sir Henry Dryden, Bart., 

 showing its similarity to a Stone Celt. 



same articles now in the museum of Vannes are described 

 by the curators Messrs. de Cusse, L. Galles, and D'Ault- 

 dumesnil z.% jadeitc'\ and ail/at.s. % 



;cs, contournees, et comme entre- 



eot son excessive tenacitc. Raie 



. Infusible au chalumeau. Les 



plus cu moins la forme d'un parallelogramme 



trapeze dont la plus graiide base oflfre un tran- 



ne substance lamelleuse. toutes les baches faites 



,ne cpaisseur faible et irrcguh^re. 



attache 



( fibres fines, soyeuse=:, t 



e veire et le feldspath, rayee par V 

 haches en fibrolite affec 

 allonge, souvent celle d'l 

 chant. La fibrolite etant 

 de cette matiere n'ont qu 



* See table. 



+ La jadcite doit etre 1 

 hydres). Couleur de di 

 jaunatre, structure cristalline, 

 rayant le feldspath et le jade 

 Facilement fusible. Une miu 

 d'une lampe a alcool, se fond 

 demi-transparent. 



X La couleur de cette matiere est le vert-pomme. se rapprochant du ve 

 de rcmeraude- Quelques echantillons sont comme marbresde parties blancbi 

 et de parties bleuatres ; d'autres sont macules de veines et de Liches bruu' 

 on noires, par suite d'un melange accidentel de matieres argileuses. I 

 :ide, i peu pres autant que la chrysoprase. Sa cassure 



a la famille des wernerites (silicate> an- 

 tinces de vert, de gris verdatre, de gris 

 ■o-lamellaire, quelque^sis un peu schistoide, 

 ntal : rayee par le quartz. Tres tenace. 

 caille, ex'posee .a lextremite de la flime 



est compacte comme celle de la cire. 11 rate le calcaii 



il est facile- 



VII. How the barrow north of Kerlescant lines can be 

 said to be related in any way (p. 356) to Mont S. Michel 

 (which is situate south-east of the Menec lines, and at 

 least a mile distant), either in position, size, or structure, 

 I cannot imagine. The former is, or rather was, a long 

 but small structure with fashioned entrances, covered over 

 with a mound which is only visible a few yards off, whilst 

 the latter is an immense tumulus, visible from afar, 

 covering one if not more kists of insignificant structure. 



VI II. Mr. Borlase's late discoveries in the dolmen- 

 mounds of Trevelgie Head, Cornwall, give additional 

 reasons for supporting Mr. Lukis' theory that both dolmens 

 and cromlechs are merely the skeletons of original cham- 

 bered tumuli. 



IX. P. 389. "Only one drawing of a dolmen in Portugal 

 has as yet, so far as I know, been published." 



In 1868 M. Da Costa figured twenty Portuguese dol- 

 mens, and eight stone implements found in connection 

 with them.* 



" In the Peninsula the cromlechs, when denuded, are 

 known under the name of Antas (a term about which 

 there has been much disputing, but which, after all, seems 

 to signify ancient altars used as landmarks) ; those par- 

 tially enveloped in the tumulus, or on the summit of a 

 mound, are termed Ulainunlias (corruption of Mamua or 

 INIamoa— tumulus) ; and when covered in, as the allees 

 and i^rottes of Brittany, they are termed Furnas. 



" In the year 1734 over three hundred of these remains 

 are mentioned as existing in Portugal, but in 1 868 M. da 

 Costa could only enumerate forty-two, of which twenty- 

 eight are in the province of Aleutejo, twelve in Beira, two 

 in Traz-os-Montes, two in Minho, whilst none remain 

 either in Estramadura or D'AIgarve. 



" The largest aggregation of these antas appears to be 

 at Contado d'Alcogulo, the property of M. Le Cocq, where 

 there are five remaining together. The only stone imple- 

 ments described by M. da Costa were found here, and 

 consist of half a dozen rude greenstone celts and a 

 quartzite muller. With the exception of four, all the 

 above. are denuded and ruined antas ; the exceptions are 

 two furnas near Vizella in Minho, the Mamunha de 

 Mamaltar in Beira, and the Mamunha de Carrazedo in 

 Traz-os-Montes. This last is chiefly remarkable from the 

 curious hollow circular mark, presumedly artificial, on one 

 of its supports. 



" There is also one curious monument mentioned, as 

 compo:ed of two rows of stones, near a menhir between 

 Cepaes and F'afe, in Minho. As this is the sole description 

 of the monument, and no dimensions are mentioned, it is 

 difficult to judge of its composition. It may be analogous 

 to two rows of small vertical stones in the long barrow at 

 Kerlescant, already mentioned, or there may formerly 

 have existed an avenue of stones. Unfortunately it ap- 

 pears that the monument has been destroyed, and the 

 stones made use of in the construction of the neighbour- 

 ing convent of Pombeiro."t 



The above remarks are not written in a carping spirit, 

 but offered merely as additional information to what Sir 

 John Lubbock aptly terms " a rich and trustworthy store- 

 house of facts," collected with such labour and care by 

 Mr. Fergusson during the last eighteen years. 



I will refrain from analysing Mr. Fergusson's theory 

 that the dolmens date from a post-Roman period in the 

 present paper. 



ment raye' par une pointe d'acier. Sa poiissiere est blanche, infusible au cha'u 

 mean. Cette substance est un phosphate d'alumine hydrate comme la 

 turquoise orientate, mais elle en differe sensiblement, aussi bien par les pro- 

 portions de si?s principes constituents que par ses caracteres. M. Damour, 

 d'apres les diflerences appreciables qui existent entre ces deux niatieres, les 

 scpare dans la classification des especes. il emprunte a plme le nom de 

 cniia^s, qu'il applique a notre mineral, et re'serve celui de turquoise a la 

 pierre precieuse de couleur bleu de ciel si connue en joaillerie. 



• "Descrip^ao de Alguns Dolmins ou Antas de Portugal," par F. A. 

 Pereira Da Costa. Lisbon, i868. 



t Vii'c "The Dolmen-Mounds and Amorpholithic Monuments of Brit- 

 tany," Part L, by S. P. Oliver, Capt. R.A , Qimrterly Journal 0/ Science, 

 Janu.-.ry .872. 



