.

I well know the Gentleman, now a Member of Parliament, who related the circumstance to me, and am positive that he would not have deceived me. I did not know of the Manchester meeting, otherwise that also would have been mentioned. My friend certainly did his part towards preventing the intended monopoly, and I have recorded the fact; but I was not bound, at the distance of 30 years, to discover what means other persons adopted to effect the same purpose.

It is also necessary for me to observe, that when Dr. Henry was complaining that in the Cyclopædia "far too little is said of the part which was taken by Mr. Watt in the application of Berthollet's important discovery," he ought to have done me the justice to remark that this was not the case in the history of the progress of the new bleaching which I had published. I have reason to say that this should have been done, because a person who had read Dr. Henry's letter has assured me that he actually conceived the Doctor had charged me with having kept Mr. Watt in the back ground as much as others had done before me. All, however, that it will be necessary for me to say in my own vindication is, that I have not only repeated what had been before published respecting the attempts of this Gentleman to promote the success of the new process, but have positively stated it as my opinion (see p. 55) "that Mr. Watt was the first person in Great Britain who introduced science into the bleaching process; for that before his connexion with Mr. Macgregor, whose daughter he had married, the whole operation of bleaching was merely the effect of observation and practice, &c. &c." This is surely another instance in which my account materially differs from that of which Dr. Henry complains. Indeed, if the Doctor will have the goodness to look again at the representation in the Cyclopædia, and then read my relation, I flatter myself that he will find the two narrations to be as different as two accounts of the establishment of any process can well be,

I perfectly agree with Dr. Henry that "it is the duty of the historian of the arts first to make himself master of the facts, and then to detail them with fairness and impartiality." In writing the history of the art and science of bleaching in this country, I do presume that I have acted in strict conformity to this rule; for when I had obtained the information I wanted respecting the introduction of the oxymuriatic bleaching into Scotland, I took the precaution, at the suggestion of the Gentleman who had given me the intelligence, of sending to Professor Copland a copy of the matter which I intended to print on this subject, being fearful that during the lapse of nearly 30 years some important circumstance might have escaped the memory of my informant. The Professor's answer, which I here subjoin, entirely corroborates the representation which I had before received, and had already given, in the body of the essay now under consideration.

The letter is dated Marischal College, Aberdeen, April 27, 1814, in which, after some introductory matter, he says, "I approve

much of the design of your present publication, and it would give me pleasure to contribute to its success, in however small a degree; and though I can add little to the account you have already received from my friend Mr. Milne, you are at full liberty to make use of it in any way you think most proper." "It was in the early part of 1787 I had the honour of accompanying the present Duke of Gordon on a tour to the Continent, during which we passed several weeks at Geneva chiefly in company with Professor de Saussure, under whose direction his Grace had studied there, in the early part of his life. Among much valuable information I received from Saussure, he showed me the experiment of discharging vegetable colours by the oxymuriatic acid, which though I had met with accounts of (I think in M. de la Metheric's Journal) I had never before seen tried. Impressed with the idea of its importance to our manufactures, and well acquainted with the chemical knowledge of the Mr. Milnes, I immediately on my return communicated it to them, and perfectly recollect our instantly trying it on a hank of yarn directly from the spinner, to which in less than an hour we gave a good white colour. To the best of my recollection this was about the end of July, 1787, and from that time I was frequently informed by Mr. Milne and his late brother that they always continued to use this new mode of bleaching in their manufactory, and particularly for finishing orders where they were limited as to time. I also think they were soon enabled to extend its application to larger quantities, by using vessels of white wood in place of glass, as at first. Mr. Milne is, therefore, in my opinion, perfectly correct in stating that theirs was the first manufactory in Britain where the new method of bleaching was introduced and continued to be practised. As His Grace dines with me to-morrow, on his way to London, before sealing my letter I shall ask his opinion as to dates, &c. and get him to direct it.

"I am with great regard,

"Sir, your obedient humble servant,
PAT. COPLAND.

To Samuel Parkes, Esq.
Goswell-street, London."

28th.-P. S. "His Grace having read the above, perfectly recollects the experiment shown by Saussure, with the opinion we both entertained of its importance; and as it may add to the authenticity of your account, permits you to use his name also in your publication."

From the testimony which this letter affords in corroboration of the foregoing details, I think I have completely established the fact that oxymuriatic bleaching was employed at Aberdeen in preparing goods for sale many months prior to any such application of it at Manchester, or at any other place in Great Britain, Mr. Macgregor's works in Scotland, where the operations of Mr. Watt were conducted, being alone excepted. But surely this circumstance does not at all lessen the merit of Mr. Thomas Henry, and other

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. Ñ.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.