
Fan. 12, 1871] 
the Mount was described by Diodorus Siculus in terms which 
apply admirably to it at present ; on the other hand, it could not 
have taken place in times geologically remote, since the forests 
consisted of plants still indigenous to the district, and contained re- 
mains of beetles retaining all their beautiful colours, as well as 
the horns of the red deer, which man had fashioned into tools ; 
that, in short, there was nothing compelling the belief that the 
subsidence happened very much before the time of Diodorus. 
The paper concluded thus :—‘‘ A careful consideration of all 
the facts of the case, as well as of the related phenomena, points 
decidedly to the conclusion that, since Cornwall was inhabited 
by a race speaking the old British language, St. Michael’s Mount 
was ahoar rock in a wood, and that its insulation resulted from 
a general subsidence of the country.” 
From the foregoing sketch it is obvious that, at that time, I 
supposed the subsidence to have taken place not much more than 
2,000 years ago, and this was well understood by Sir C. Lyell 
and others, who took part in the discussion on the paper. Indeed, 
the eminent geologist just named, to whom I soon after sent the 
manuscript, after speaking of the attention I had given to the 
question (Principles, vol. 1. p. 543, 1867), adds, ‘‘ It is a some- 
what forced hypothesis to assume that, whereas a retrospect of 
nineteen centuries displays to us the Mount geographically the 
same as it is now, yet shortly before that time, when Cornish was 
spoken, there was a sinking down and submergence of a wooded- 
tract ;” thus stating his dissent from the view which, as he knew, 
I then held. 
Aiter reading the paper of 1865, I devoted considerable atten 
tion to the literature of the subject, and in the lecture of 186 
stated that the tradition of the Mount having been five or six mile 
from the sea, and enclosed in a very thick wood, was first men 
tioned, not by /Vlorence of Worcester, who died in 1118, and who 
nowhere alluded to the Mount, but by /V//iam of Worcester, 
who visited Cornwall about 1478, or 360 years further from th 
period to which the tradition was supposed to point, thus rene 
dering the tradition itself of very much less value; that the- 
alleged old Cornish name assumed so many forms, and there was 
so much uncertainty about its exact import, as to render it im- 
probable that it had any value as evidence ; and that the sub- 
merged forest in Mount’s Bay was known much earlier than I had 
supposed, having been mentioned by Leland, 1533-40. 
The object of the lecture was to show that there had been a 
general subsidence of the country, that this was prior to the time 
of Diodorus, and that the era of the cavern deposits in South 
Devon was much earlier still. In fact, the insulation of the Mount, 
which was held to synchronise with this subsidence, was used as 
the first, or most modern, of a series of stepping stones leading 
backwards towards the era of the ancient Cave-men of Devon. 
The printed abstract of the lecture closes with a recapitulation, 
which contains the following passage :—‘‘ Nineteen centuries ago 
it (the Mount) possessed a safe harbour, so that its insulation 
must have been effected long before ; it was at one time unques- 
tionably a hoar rock in a wood, but in all probability it had 
ceased to be so long before any language now known to scholars 
was spoken in the district. Prior to its insulation was the era of 
the growth of the forests now swdmerged along our entire sea- 
board,” &c. ‘ 
Tam not quite sure to what Prof. Max Miiller refers when, 
speaking of this lecture, he says, ‘‘ Mr. Pengelly has somewhat 
modified his opinion” (p. 333). If to the opinion that the 
insulation of the Mount was due to subsidence, he is unquestion- 
ably in error, as I have never wavered on this point. If to that 
of the old British language having been spoken in Cornwall 
20,000 years ago, my reply has already been given—‘‘ I never 
held it.” But if it be to the opinion that there was a fair amount 
of evidence in tavour of the traditions of the enclosure 
of the Mount in a thick wood, and of its alleged old British 
name ; instead of modifying, I had discarded it in 1867, and with 
it, asa matter of course, the necessity of believing, on the one 
hand, that the Cornish language must have had an antiquity of 
20,00 years ; or, on the other, that the subsidence took place 
but little more than 2,000 years ago. It is unnecessary to say 
how very much I am gratified at finding the traditions discarded 
also by Prof. Max Miiller (see p. 355 e¢ seg.) 
Before concluding, I may state that in July 1867, I read a 
paper to the Devonshire Association, under the title of £e-The 
Antiquity of Man in the South-west of England,” which was 
simply an amplification of the lecture of the previous April, and 
was printed 77 extenso in the following October.* It contained 
* Trans, Devon Assoc., vol, ii. pp. 129—161, 1867. 
NATURE 

207 

a few points of interest which had come to my knowledge after 
the Royal Institution lecture was delivered ; such as the fact that 
the earliest mention of a British name was made, not by Carew 
in 1602, but by Norden in 1584 and Camden in 1586, who con- 
curred in giving it as ‘* Careg Cowse,” which the first rendered 
the Grey rock, and the second Rupis cana; the fact that the 
name occurred in two different forms in Carew ; and the fact 
that there was some error in William of Worcester’s statement 
about Pope Gregory’s grant to the Church on the Mount in the 
year 107¢, there being no Pope Gregory at that time. 
It is not my intention at present to enter on a consideration of 
the question, ‘‘Have geologists,” as Professor Max Miiller sup- 
poses, “‘ left it doubtful whether the insulation of the Mount was 
due to the washing of the sea-shore, or to a general subsidence of 
the country ?”’ or, ** May not the Mount have always been that 
kind of halfisland which it certainly was 2,000 years ago?” 
My object is simply that of correcting an error into which 
the Professor has fallen respecting my opinion, apparently in 
consequence of using an anonymous and probably incorrect 
report of a paper read in 1865, instead of an authorised abstract 
of a lecture delivered in 1867,—an error, however, which can 
scarcely be regretted, since to it we owe a “Chip” of great 
interest and value. W. PENGELLY 
Lamorna, Torquay, Dec. 26, 1870 

, Glycerine Solutions of Pepsin and other Substances 
In NatTuRE of December 29, Prof. M. Foster calls attention 
to the method of making glycerine extract of pepsin pursued by 
Von Wittich, and remarks with reason that the means hitherto 
adopted for preparing pepsin for medical purposes are clumsy 
and inefficient. There is, however, one exception, a mode of 
preparation which has long been in use, and which is by no 
means inefficient. This will be found to possess some practical 
advantages over the process of extracting the fresh mucous mem- 
brane with glycerine, while from it the glycerine solution can be 
prepared quite as pure and clear, and as strong as by maceration. 
As long ago as 1858 (Archives of Medicine, vol. i. pp. 269-316) 
Idescribed a method of obtaining the active digestive material 
from the pig’s stomach, which answers perfectly, and has been 
employed in practice ever since. It simply consists in quickly 
drying the mucus expressed from the stomach glands upon glass 
plates.* The dried mucus is then powdered and kept in stop- 
pered bettles. It retains its properties for years. Eight-tenths 
of a grain will dissolve ove hundred grains of coagulated white 
of egg. 
Now, from this powder is easily prepared by solution in dis- 
tilled water a perfectly clear and colourless digestive fluid of 
great activity, which caz be readily filtered. 
Some years ago I found great advantage from subjecting 
tissues to the action of a very small quantity of this solution in 
glycerine, and keeping the whole at the temperature of 100° for 
some hours. By this process the elements of the tissue were 
softened, and could be dissected from one another readily for 
examination under the highest magnifying powers. 
No doubt there is much to be learnt concerning the nature of 
the action of such substances upon tissues by the use of glycerine 
solutions. For microscopical work glycerine is of more use than 
any other medium. Not only may various substances be re- 
moved from tissues, but others may be introduced, and the tissue 
subjected to the action of various reagents without destroying it. 
In fact, the action may be regulated with the greatest nicety. 
Nearly all the tests required in nvicroscopical examination may 
be dissolved in glycerine (‘‘ How to Work with the Microscope, ” 
p- 297, 1867) and tissues of the most delicate character may be 
preserved in it, and will retain their microscopic characters for 
years, if care be taken to obtain the best and strongest glycerine, 
LIONEL S. BEALE 
Tails of Comets, Solar Corona, and Aurora 
UNDER this heading, in your issue of 5th inst., you report a 
paper by Prof. Osborne Reynolds, M.A., read at a meeting of 
the Manchester Literary and Philosophical Society, Nov. 29 
last. This paper sets forth that the tails of comets, the solar 
corona, the aurora, and the Zodiacal lights are due to the ether 
which ‘‘fills” space. Comets’ tails, as stated by the Professor, 
in his paper, are an effect due to the medium through which it 
* This Pepsin is prepared for medical purposes by Messrs, Bullock and 
Reynolds, 3, Hanover Street, Hanoyer Square, 
