116 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
This, taken in conjunction with a general accordance with their other com- 
ponents, shows that these specimens are similar to other vein-serpentines, and 
are quite distinct from the mineral which occurs in volcanic rocks. | 
As the specimen sent by Professor Kine is quite similar to other smaller 
ones which I have seen in the Lizard serpentine, there is every probability that 
the mineral analysed by KLAPROTH, SVANBERG, and HAUGHTON was the same ; 
and that of the substances classed under the head of saponite by Dana, only 
those narrated as filling geodes in volcanic rocks properly fall under the title. 
SUPPLEMENT TO CHLORITE. 
I have lately observed what I believe to be a chloritic mud occurring in a 
form in which it bears a great resemblance to glauconite. 
The circumstances of its occurrence are of much interest, and the explana- 
tion of these circumstances is attended with no small amount of difficulty. 
Immediately to the north of the village of Callander there is a cliff of 
conglomerate of the Old Red Sandstone ; this is here formed of nodules, from 
the size of a walnut to that of the fist, of gneiss, mica slate, and quartz,—rocks 
of the immediate neighbourhood. 
Rarely thin interstrata of a finer almost of a sandy grain,—more fitted for 
building purposes,—occur to the north-eastward of the village. 
In several small quarries, opened with a view to work these gritty beds, the 
characters of the conglomerate may be studied. It has somewhat of a vitrified 
aspect, and is more broken up by “backs” and “cutters” than is usual to that 
rock. The dip is to the north-east ; the backs run along the strike at distances 
of about six feet from each other; while the cutters, lying generally at right 
angles thereto, are much more closely adjacent to each other. 
The backs, in those cases in which they have stood open, are invariably 
filled with one of the varieties of the substance to which the names of reddle, 
or keely or keels has been attached: the cutters are as invariably lined, and 
usually no more than lined, on each side with sheets of cockscomb barytes, 
which sometimes carry vitreous copper, malachite, and calcite. 
The dull red of the vertical sheets of reddle is everywhere besprinkled with 
spots and blotches of a vivid green, of the colour of glauconite,—these spots 
are circular in form, or consist of a number of confluent circles, each circle being 
of about the size of a large bean. 
The contrast of these colours is so striking as to arrest the attention of the 
passer-by ; it is found upon examination to be due to the occurrence in the 
