46 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
cessful research in geology consisted in his once having discovered “an unques- 
tionable specimen of petrified maggots” in a pigstye, and whose faith therein 
was only slightly shaken after a dire amount of argumentation. Had he cast 
eye on one of these slabs, he would, in all probability, have believed in petrified 
maggots to the end of his days. 
The specimens of this mineral which were analysed were got in North Glen 
Clova, where it is somewhat rare. They were specially selected on account of 
their being much lighter in colour, and hence apparently purer than those 
ordinarily procurable. This lightness of colour might, however, be due to 
incipient weathering. In appearance they were very similar to the paragonite of 
Monte Campione ; indeed, they were supposed to be that mineral. They were 
scaly in structure and cream-coloured; soft and somewhat unctuous when 
rubbed along the lamination of the scales, but rough when rubbed across it. 
They contained throughout their mass minute almost invisible crystals of 
magnetite ; these were separated, it is believed absolutely, by crushing, repeated 
edulcoration, and sifting with a magnet. 
The mineral absorbed *579 per cent. of moisture. When slightly heated in 
powder before the blowpipe, there was a slight decrease in bulk and the assump- 
tion of a brown colour; when highly heated the contraction is very marked, 
and the powder agglutinates and shows traces of vitrification, the original colour 
being restored. 
The two specimens analysed differed very slightly in appearance. 
On 1°3185 grammes. On 1°584 grammes. 
Silica, : ‘ . vow o2e 61 sd 
Alumina, , : « 26 °455 26516 
Ferrous Oxide, . ee 2 9 2° 556 
Lime, 2 : : "467 * 669 
Magnesia, . : : *568 "694 
Potash, . ; Sb STS n. det. 
Soda, ; : wid *685 n. det, 
Water, . ; . 4,847 4°23 
100+ 611 
Insoluble silica of first, 1° 842 per cent.; of second, 1°584 per cent, 
Possible impurity, magnetite or quartz. 
