350 PROFESSOR HEDDLE ON 



Saussure, Jils, describes it under the name Sappare, in Journ. de Phys., xxxiv. 

 213, 1789. His name sappare arose from a mistake in reading a label of the mineral, on 

 which it was called sapphire ; a copy of this label is given in the Journ. de Phys. 

 The specimen thus labelled was from Botriphnie in Scotland, and was sent by the 

 Duke of Gordon to Saussure the father. 



In the Descr. Cat. de VEcole des Mines, p. 154, published by Sage in 1784, it is 

 called Talc bleu ; but as the present writer found no "Talc bleu" in the collection of 

 l'Ecole des Mines, and as he among the specimens of kyanite found a Botriphnie 

 specimen of the. mineral, it is probable that had been the specimen termed the "Talc 

 bleu " by Sage, and the specimen presented by Saussure, having come from the same 

 original source. 



The name sappare was used for the mineral by some writers up to 1823, when we 

 find it employed by James Smithson who, in virtue of its infusibility, used it as a 

 support in blowpipe experiments.* 



Kyanite is no longer got at Botriphnie, and the precise spot where it occurred I have 

 not been able to find. Specimens from this locality are in the collection at Jermyn 

 Street Museum, and in those of Edinburgh, Banff, and, I think, Montrose. They were 

 larger and finer than any now obtained in Scotland. The only associated mineral is 

 margarodite. 



The second locality at which this mineral was found in Scotland was in the vicinity 

 of the Burn of Boharm, about a mile above the house of Auchlaukart — that at least is 

 the spot where the writer has found it in North Boharm. 



Dr Macculloch, in writing of it at this spot, gives the following accurate description 

 of it, one which should be pondered in considering the metamorphism of the rock matrix. 



"Boharm. This sappare-disthene is said to have been originally discovered in this 

 place. The crystals occur in a quartz vein which traverses a talcose clay-slate. They 

 pass through both without any change of their direction or appearance ; seeming to 

 mark a common condition in the schist and the quartz at the period of their formation. 

 Although these crystals in general penetrate and impress the quartz, they are sometimes 

 bent and waved, as if they had accommodated themselves to its irregularities. This is 

 not the case, however, with those imbedded in the talcose slate, which radiate in bra 

 of rectilinear crystals through its mass. This rock consists of a talcy clay-slate, so 

 penetrated with hornblende as to render its character for an instant doubtful. On an 

 accurate examination it will be seen that the body of the rock is a clay-slate, and that 

 it is interspersed throughout with lamellar and thin crystals of hornblende. These 

 lamellaj are generally disposed at right angles to the lamella of the schist, and are some- 

 times short and straight, and variously placed, interfering with each other often in every 

 direction. More commonly they diverge from a sort of central axis in curved planes, so 



* Smithson remarks : " Chemical analysis carries destruction along with it, and bestows knowledge of a rab- 

 stance only at the cost of its existence. One remedy which can be offered for this defect is to reduce the scale ol 

 operating, and thus as far as possible reduce the amount of the sacrifice." 





