deserving individuals, in whose behalf Dr. Henry has so zealously appeared; for the Doctor need not be told how many instances we have of chemical discoveries being made by persons at a distance from each other, and who had enjoyed no previous intercourse whatever.

I cannot conclude this part of my reply without acknowledging the handsome manner in which Dr. Henry, in the supplement to his letter,* has spoken of my intentions; and I am confident that he will do me the justice to believe that in this communication I have been actuated by no motive whatever except the desire of justifying myself both in his view and in that of the public.

Respecting Mr. Thomas Henry, I am free to confess that I have not done him all the justice which I would have done had I been in possession of those facts which Dr. Henry's letter now communicates. I have reason to believe that I had heard something of the exertions of Mr. Henry towards establishing the process in Manchester; but this was several years ago; and the matter was never in my recollection while writing the detail in which his name ought to have had a prominent situation. I am the more surprised at my having thus forgotten Mr. Henry, when I perceive that I have spoken of him at p. 85 as the inventor of a method of bleaching the grounds of printed calicoes that have been dyed with madder, an invention of great importance, and which was afterwards communicated by Berthollet to M. Obercamp, an eminent printer at Jouy, who embraced the proposal, and continued the practice ever afterwards.

I trust, however, that Mr. Henry, whose very amiable character and eminent attainments in science have long secured for him the respect and esteem of all who know him, will not for a moment imagine that this great omission could have occurred from design; and I now assure him that whenever there shall be occasion for a second edition of the Essays, none of his exertions for perfecting so important an art shall be left unrecorded.

Goswell-street, London,

I am, Sir, with great respect,

Your most obedient humble servant,
SAMUEL PARKES.

Jan. 6, 1816.

ARTICLE III.

On Mineralogical Surveys. By Robert Jameson, Esq. F.R.S. E. Professor of Natural History in the University of Edinburgh.

SOME time ago, at the desire of an accomplished and patriotic Nobleman, Lord Gray, I drew up the enclosed plan of a mineralo

* Annals of Philosophy for December, 1815, p. 472.

gical description of the county of Perth. As it may prove interesting to some of your readers, I hope you will insert it in your Annals of Philosophy.

I remain, my dear Sir, yours truly,

45, George-square, Oct. 30, 1815.

ROBERT JAMESON.

I. Geographical Part.

1. General and particular geographical account of the county. 2. Description of the surface of the county.-A. Ranges of mountains. Extent, mode of connexion, shape, acclivities; heights as ascertained by the barometer.-B. Single mountains. Shape, acclivities, magnitude, height.-C. Valleys. Extent, shape, character of cliffs and precipices, inclination and nature of the bottom, height above the level of the sea, and mode of connexion with neighbouring valleys.-D. Plains. Extent, appearance of their surface, height above the sea.

3. Description of rivers. Magnitude; under which is included their length, breadth, and depth; falls; height above the level of the sea at different points of their course; nature of their banks; character of their scenery; comparison of their former with their present state; the physical and chemical properties of their water; temperature; and, lastly, descriptions or accounts of the animals and plants that inhabit them.

4. Description of lakes. Magnitude; under which is included their length, breadth, circumference, and depth; temperature at different depths; colour; height above the level of the sea; chemical properties of their waters; animals they contain; plants that grow in them; character of their scenery.

5. Description of springs. Magnitude; temperature; height above the level of the sea; rocks from which they issue; their chemical and physical properties; incrustations found around them; uses; plants that grow in their vicinity.

6. General observations on the physiognomy or surface of the county, in relation to the other counties in Scotland.

II. Mineralogical Part.

1. Description of the different soils, according to a new method; also chemical analyses of the more remarkable and curious soils.

2. Description of bogs and mosses. Their magnitude; height above the level of the sea; different kinds of peat they contain; various organic remains found in them; uses; draining, &c.; plants that grow on their surface, and animals that live on and near them; chemical composition and properties of the different varieties or peat.

3. Description of marl beds. Their length, breadth, and depth;

their height above the level of the sea; rocks on which they rest; the substances with which they are intermixed, and the alluvial matter and soil which cover them; chemical examination of the different marls; uses, and mode of digging and searching for them.

4. Description of the different rocks of which the county is composed, according to their various mineralogical relations. N.B. This very extensive and interesting part of the Report will contain a variety of sections illustrating the internal structure of the ranges of mountains, and showing the rocks of which they are composed. 5. Mineralogical description of the mineral veins and beds that occur in the county.

III. Economical Part.

1. Descriptions and chemical analysis of the different kinds of ores found in the county. The mode of mining in particular spots depending on their local situation, the expense of mining and quarrying, and the particular tracts pointed out where trials of greater or less extent may be advantageously carried on by proprietors.

2. Descriptions of the different kinds of lime-stones and marbles; quarter of the county where they occur, magnitude of the beds, mode of quarrying them, and proposed economical kiln for burning the lime-stone; chemical analyses of the different lime-stones and marbles in the county, with the view of ascertaining their value in agriculture, building, and statuary.

3. Descriptions of the different kinds of slate that occur in the county; places where the best kinds are found; mode to be followed in quarrying them; characters to be used for distinguishing good from bad slate; and a statement of those symptoms that indicate the presence of slate.

4. Descriptions of the different species of precious stones that occur in the county; places where found, mode of searching for them, and of estimating their value.

5. Descriptions of the different kinds of building stones found in the county; places where found; most eligible spots for quarrying them; mode to be followed in quarrying them; and the kinds of building for which the different sorts are best calculated.

6. General observations on the probability of finding coal in the county, with a statement of the best mode of following out such favourable appearances as may occur.

7. General observations on the mineral riches of the county, and a comparison of its mineralogical structure with that of other counties.

To contrive a cypher which shall be at once secure from detection, and easy in its application, has been considered a problem of some difficulty; and if we may judge from the failure of several very well contrived attempts, such a cypher is still a desideratum. One of considerable difficulty was proposed in Dr. Rees's new Cyclopædia; but this has been decyphered by Mr. Gage. Another cypher, contrived with great ingenuity, was proposed by Professor Herman about the year 1750. It was offered with great confidence as a challenge for the learned of Europe. It was, however, decyphered a few years after by M. Bequelin, who read a memoir on the subject to the Academy of Sciences of Berlin, which was published in their Transactions for the year 1758. This paper contains an explanation of the law of the cypher, and is perhaps the most elegant specimen of reasoning on this subject which has yet appeared. It might well be selected as a model for all future inquiries of a similar nature. The two cyphers just alluded to are perhaps amongst the most difficult that have been contrived; but notwithstanding their failure, I will venture to propose the annexed as a specimen of a cypher which possesses very considerable advantages over either of them. In point of simplicity it yields to none; for each character represents a letter; consequently the cumber of characters to be written does not exceed the number of letters. the former of the two cyphers just mentioned each letter is represented by two characters; and in the latter one letter is sometimes denoted by the combination of three characters. In point of security, the cypher which I propose will, I imagine, be found unexceptionable. It is constructed purposely with a view to defeat all the rules of decyphering; and though the translation of this specimen were to be given, yet I am convinced the cypher would remain secure. With respect to the number of varieties of which this cypher admits, it is unlimited; and the key itself may be changed with equal facility at every line or at every letter. Combining such advantages, it might be imagined that this cypher is encumbered with laws which would render it too tedious for

tice.

In

prac

This, however, is by no means the case. When the key is known, it is easy to interpret it; and such is its simplicity, that no written memorandum of the key need be preserved; for it may be written out at any time without scarcely the least effort of the memory.

C. B.

VOL. VII. N° II.

H

Account of the Worm with which the Stickleback is infested.
By Thomas Lauder Dick, Esq. With a Figure.

SIR,

(To Dr. Thomson.)

Relugas, near Forres, N. B. Nov. 17, 1815. GMELIN, in his description of the gasterosteus aculeatus, or three spined stickleback (Syst. Nat. p. 1323), says of that fish "vermibus intestinalibus tanto crebrius infestatus." And Mr. Donovan, in his splendid work on British fishes also remarks with regard to this gasterosteus that "Frisch, Pallas, and M. Fabricius, who have entered into their history, observe that it is greatly tormented with worms at certain seasons, a fact sufficiently obvious to every common observer." Although this circumstance in the natural history of these fishes appears thus to be already generally well understood, yet the following particulars, which I now presume to offer you, may not perhaps be altogether unacceptable.

Early in the month of June last my neighbour and friend Mr. Brodie, of Brodie (a Gentleman well known as a naturalist), had about 50 or 60 of the three spined sticklebacks brought to him alive in a vessel of water from one of his ponds. Most of these little fish presented the ordinary appearance; but many of them were of a form so very singular as to induce me almost to hesitate in pronouncing, at first sight, whether they were the same animal or not. Supposing the head and shoulders to have been removed,