114 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
This is very like a Hullite in which much of the iron is in the ferrous con-_ 
dition, 
These two substances are noticed in the hope of more of them being found ; 
the quantity obtained of both of them was very small. 
SUPPLEMENT TO SAPONITE. 
In a letter from Professor Kine, received since the foregoing analyses of 
saponite were executed, he writes :— 
“ According to HAUGHTON, saponite occurs with serpentine in Cornwall. 
Some specimens I collected there I take to be the same mineral; but it is not 
‘soft like butter or cheese —it is hard, something like serpentine, and may be 
actually a white or cream-coloured serpentine. The specimen laid by for you 
will settle the point. I should like to see your saponite.” 
This sentence led me to compare the specimens which I have of what I 
have called the ‘“ super-hydrated vein-serpentine” (page 109) with the descrip- 
tions of saponite given by Dana,—and my analyses of these specimens with 
the column of analyses to be found at page 472 of his work. 
While the physical properties assigned to saponite by Dana agree perfectly 
with those of the specimens which I have analysed, and therefore warrant my 
assigning the name to the Scotch specimens, it cannot be said that the claim 
of certain of Dana’s specimens to the name is altogether beyond a doubt, and 
this on account of the most characteristic of the features of the Scotch 
mineral—namely, the low temperature at which it parts with some of its water 
—not having been observed in the specimens hitherto ranked as saponite. 
When, however, the analyses given by Dana are considered, there is no room 
for doubt that some of the substances analysed should not have found a place 
there, and there is even room for doubt if any but the ¢halite of OWEN should. 
Nothing, but their having suffered such a loss of water as I have pointed out 
as likely to occur through exposure to heat during carriage, could entitle us to 
associate under one name substances varying in their content of water to such 
an extent as from 10°5 to 20°66 per cent.—a variation which so far explains, 
though it hardly justifies, Dana’s remark, that “analyses give naturally no 
uniform results for such an amorphous material.” Had it been said that the 
name had been applied to substances which, filling the steam-holes of volcanic 
rocks, were unquestionably the products of change or degradation,—possibly 
not always of the same nature, or of the same material,—such a remark might 
legitimately be made. It is, however, a fairer inference that the analyses give 
no uniform results, because different substances have been included under one 
name. 
