3. The chemical compounds formed in the wood by this process are: First. Compounds of copper with the organic constituents of the wood.

Second. Cupric chloride and baric sulphate, wherever the solutions of copper and baricum meet.

The compounds of copper with the organic matters of the wood strongly resist putrefaction. The cupric chloride, and any excess of cupric sulphate not acted on by the baric chloride, would also "tend to the preservation of wood."

The baric sulphate is a practically insoluble salt, and, so far as any chemical action on the wood, or poisonous action on organisms is concerned, is inert. Its action, if any, must be mechanical only. That it does not, to any appreciable extent, occlude the pores of the wood is evident from microscopic examination as well as from the minute quantity present. It is not apparent, on any theoretical grounds, that the barium salt in this process would "tend to the preservation of wood."

4. A salt of copper in solution brought in contact with iron tends to the deterioration of the latter. But it is probable that in this instance the quantity of copper salt present in the impregnated wood is insufficient to effect any practical injury to the bolts and spikes which would be used in it. So long as the wood is kept dry no action upon the iron would take place.

5. Three specimens of wood, said to have been treated by the process of the American Wood Preserving Company, have been brought before the board.

First. A spruce railroad tie, from Germany, bearing the seals of the United States legation, said to have been in use sixteen years. The wood is still in a good state of preservation and serviceable.

Second. A beech railroad tie, said to have been in use nine years. It is also well preserved and fit for further use. A copy of a letter authenticating these specimens will be found appended (marked B).

Third. A plank walk in the navy-yard, Boston; letter from Civil Engineer U. S. G. White, U. S. N., in reference to the walk, is appended (marked C').

The planks of this walk appear to be perfectly sound and unaffected by exposure to the elements.

The undersigned desires to remark, in connection with section 3, that the expression "it is not apparent, &c.," used at the close of the section is accurate in so far as (1) it refers to the baric sulphate, an insoluble salt, formed during the process, and (2) the small amount of the baric salt found by the analyses, and no farther. Regarding it as quite possible to impel a much larger amount of the baric chloride into timber than was done for the present occasion, it is equally possible, and in that event probable, that some of the baric chloride would escape contact with the cupric sulphate. It would then be quite free to combine with the same kinds of organic matter of the wood as the copper (as has been stated in the text) does. Such a compound would be quite as insoluble and quite as efficient a preservative agent as the copper salt. And as a further illustration of the probable value of the baric salt, it is the opinion of the undersigned that a compound may be formed with the cellulose of the wood. This is an hypothesis yet to be verified. And in connection with section 4 he desires to say that, from the statements therein made, it might be inferred that should the timber become wet some electrolytic action tending to decompose the iron might result, however immaterial as to extent, for the reasons there given, it may be from a practical point of view. While in section 3 it is stated that the compounds formed in the reactions with the cupric sulphate are

(1) Organic compounds, and

(2) Baric sulphate and cupric chloride.

It should be stated here that the organic compounds are insoluble in water, and are formed (1) by reaction with the cupric chloride, and (2) by any excess there may be of cupric sulphate, that is, as much of the latter as is not acted upon by the baric chloride. Since, then, the organic compounds are insoluble, and cannot therefore become electrolytes, the allusion to the possible slight decomposition of the iron assumes the possible partial failure of the cupric salts to combine with the organic matter to

form insoluble compounds with it, and, as a matter of course, the existence of free soluble copper salts.

The undersigned, in signing the report, grants this assumption, remote though the possibility may be. We have, then, by the terms of the assumption, free copper salts within the timber.

For purposes of explanation, it may be further assumed that they are present in sufficient quantity to injure the iron under favoring conditions. It is the opinion of the undersigned, 1st, that the conditions required, viz, a free solution of the salt and freedom of the iron from contact with protecting matter could not exist, and, 2d, that, admitting their existence, the means whereby the solution would be effected would prove the means of preventing the decomposition by removing the cause, for an affirmation of an ingress of the solvent in this case predicates an egress of the solution by diffusion in the surrounding menstruum, in obedience to well known laws.

W. M. MEW, Acting Assistant Surgeon, U. S. A.

A.

NAVY DEPARTMENT,

Washington, June 23, 1881.

SIR: You are hereby appointed president of a board, to consist of yourself, Dr. W. M. Mew, of the Surgeon-General's Office of the Army, and Dr. F. W. Taylor, of the Smithsonian Institution, to assemble at the navy-yard, Boston, on the 28th instant, to examine into the process of preserving timber for naval purposes by the American Wood Preserving Company. The duties of the board will be to determine and report:

First. Whether the impregnation of wood, as practiced by the American Wood Preserving Company in the Charlestown navy-yard is a practical preventative of rot and decay in those parts of the wood which are liable to such action by the elements, and the ravages of the organism which, in common language, powderposts the wood. Second. How far the salts of copper and barium, by this process, are made to penetrate the wood for such purpose.

Third. Whether the chemical compounds formed in the wood by this process are such as, upon well sustained chemical theory, would tend to such preservation.

Fourth. Whether there is anything in the process which would tend to the deterioration of the iron bolts and spikes which go into the wood; and

Fifth. To examine such specimens of the wood, so preserved, as may be authenticated to them to have been in actual use, and report the condition in which they are found, the time of such use and exposure to the elements.

For this purpose you will proceed to Boston in season to organize the board at the time herein indicated, and return to Washington when the duties of the board are completed.

The commandant of the navy-yard will be instructed to afford the board such facilities as may be at his command.

The board will make their report in writing to the department.

Very respectfully,

SIR: In compliance with the request of the board, I herewith hand you three sections of a beech tie, preserved by the American Wood Preserving Company's process, laid on the Cleveland and Pittsburgh Railroad in March, 1870, in use nine years when taken up; it is certified to by J. R. Conrad, assistant superintendent and treasurer, on page 14 of the American Wood Preserving Company's circular, also by Charles H. Strong, city civil engineer of Cleveland, Ohio, on page 15.

I also hand you three sections of a spruce tie, impregnated by the American Wood Preserving Company's process, which was taken up after being down sixteen years in Germany, certified to under the seal of the legation of the United States at Berlin, which tie with the seals were examined by the board at our works, Charlestown navy-yard.

I have the honor to be, your friend and servant,

JAMES H. YOUNG

Managing Director American Wood Preserving Company.

Dr. J. M. FLINT, U. S. N.,
President Board, United States Navy-Yard, Boston, Mass.

C.

NAVY-YARD, BOSTON,

Civil Engineer's Office, July 5, 1881.

SIR: In September, 1879, I put down a plank walk along the rope-walk building, from lumber treated by the Thilmany process for the preservation of wood, and so far the results have been entirely satisfactory. The walk is in a position which exposes it much to rot and decay, and before I put down the treated wood I was continually making repairs which amounted to a renewal at least once in two years.

Respectfully,

Dr. J. M. FLINT,

W. S. G. WHITE, Chief Engineer, U. S. N.

Surgeon, U. S. N, Navy-Yard, Boston.

No. 5.-REPORT OF DR. WILLIAM N. MEW.

General Benj. F. Butler to Dr. Wm. N. Mew, analytical chemist, A. A. surgeon U. S. A., in charge of laboratory, Army Medical Museum, relative to his conclusions as one of the board of experts appointed by order of the Secretary of the Navy, 23d June, 1881, on American Wood Preserving Company's process. Washington, D. C., December 23, 1881, Dr. Wm. N. Mew to General Benj. F. Butler.

WASHINGTON, D. C., December 22, 1881. DEAR DOCTOR: I have read your report in the matter of the American Wood Preserving Company's process as practised in the Boston navy-yard, and while it is perfectly satisfactory to a scientist I doubt not, yet to the common comprehension of those to whom your report would have weight if the American Wood Preserving Company should be allowed to publish it for public information, the scientific results to which you arrive may not be fully appreciated. Will you therefore state in plain language your opinion upon the following questions:

First. Whether the process of impregnation of wood for the purpose of preservation by copper and barium as used by the American Wood Preserving Company in the navy-yard at Boston is, upon well approved scientific principles, adapted to its preservation from rot and decay.

Second. Whether, from all the evidence that was placed before you, you believe that practically such process does preserve wood from rot and decay.

Third. It has been objected to the process that it might deteriorate the iron so as to materially lessen its strength, which should be used in fastening the timber. I should like your opinion on that point, and as corollary to this question: Whether if such preserved timber should be used either as a covering or lining for iron ships, there would be any appreciable deterioration of the iron because of such impregnation?

Fourth. Whether as a government officer you are of the opinion that the process should be applied to the timber of vessels for the purpose of preserving them at least until the actual use of such timber demonstrates the usefulness of the process? Fifth. What, in your opinion from all your examination, will be the result of such an experiment when put into practice?

I am yours, truly,

Dr. WM. N. MEW,

BENJ. F. BUTLER.

Washington, D. C.

WASHINGTON, D. C., December 23, 1881.

DEAR GENERAL: I have the honor to acknowledge the receipt of your letter of yesterday's date, requesting me to give, in unscientific language, my opinion upon certain points therein stated, covering substantially the problems submitted to the board, of which I had the honor to be a member, which met in Boston in June last to examine into the value of the American Wood Preserving Company's process.

1st. Whether the process is, upon well-approved scientific principles, adapted to the preservation of wood from rot and decay.

I answer this affirmatively, and that it depends for its value mainly upon the formaation of insoluble and, therefore, as to putrefactive changes, indestructible organic metallic compounds.

2d. Whether, from the evidence placed before me, I believe that practically the process does preserve wood from rot and decay?

To this I answer that I have not the shadow of a doubt of it; the evidence was con

*

clusive to me, and in my opinion a contrary view could only be held in violation of the plainest application of the logic of scientific evidence.

3d. As to the effect of the copper salts upon iron bolts, I unhesitatingly affirm that I know of no condition of actual practice in which decomposing action (electrolytic change) could take place; my views are the same with regard to ships built of iron and lined or sheathed with preserved planking.

4th. "Whether, as a government officer, I am of the opinion that the process should be applied to the timbers of vessels for the purpose of preserving them at least until the actual use of such timber demonstrates the usefulness of the process ?"

I reply that, being thoroughly convinced of the value, I would regard its discontinuance as wholly unwise; I venture to add, absurdly so. In view of the fact that theoretical considerations favor it, and that every test by actual use has shown its value, it should not, in my judgment, be abandoned until it shall be shown by actual trial to have seriously failed.

5th. "As to what, in my opinion, from all my examinations, will be the result of such experiments if put into practice ?"

I reply that the durability of the timber will be very largely increased, that the expenses of repairing vessels will be commensurately diminished, and that, therefore, it would prove an important measure of economy.

Very respectfully, and very truly, yours,

General BENJ. F. BUTLER,

WM. N. MEW,

Analytical Chemist and A. A. Surgeon, Ú. S. A.

Washington, D. C.

No. 6.-REPORT OF NAVAL CONSTUCTOR WM. L. MINTONYE.

UNITED STATES NAVY-YARD, BOSTON, Naval Constructor's Office, March 6, 1882. SIR: In reply to your letter of the 1st instant I have the honor to state that on September 30, 1875, I was ordered by the Chief of the Bureau of Construction and Repair to proceed to Cleveland, Ohio, and carefully examine into the process of preserving timber by the American Wood Preserving Company.

After looking at some railroad ties that were said to have been in use eight yearsand certainly they looked as if they had, and were sound-and some street pavement that had been down four years, I came to the conclusion that it was worth while to make some practical experiments with this process of preserving timber.

Several small trees were cut down and impregnated, green. A piece of seasoned impregnated timber was found to be rotten after I left and condemned.

Í reported that, from what I had seen, timber lasted longer that had been treated than timber not treated under the same conditions, and as the company was willing to send samples to be tried, I recommended that a practical test be given them by putting some pieces in the Trenton, then building at the Brooklyn navy-yard.

The company sent the timber, but I did not hear from my report, and thinking that the authority would be given, Í had a piece of each of those trees put in the port battery aft of the quarter-gallery port, and for my own information and in justice to the company I procured the borings referred to.

As I did not feel justified in making any tests in the immediate vicinity of this material, I cannot say how it compares with that, but all that had been cut out was rotten, while those four strakes bored sound.

I would suggest that one of the four strakes, impregnated, be cut and compared with the material in the immediate vicinity.

Very respectfully, your obedient servant,

Hon. WILLIAM H. HUNT,

Secretary of the Navy.

W. L. MINTONYE, Naval Constructor, U. S. N.

No. 7.-REPORT OF THE CHIEF OF THE BUREAU OF ORDNANCE,

BUREAU OF ORDNANCE, NAVY DEPARTMENT,
Washington City, February 3, 1882.

SIR: Agreeably to your verbal instructions, I beg leave to make the following remarks upon a number of papers (submitted to me) concerning the questions at issue between the department and the American Wood Preserving Company.

On examination, I find that on February 8, 1877, the department made a contract

with the American Wood Preserving Company, calling for the impregnation, by the company's process, and under its patent, of a quantity of timber, certain conditions as to plant, labor, &c., being laid down. Those points in the contract that are material to the inquiry now being made are as follows:

After payment for 100,000 feet at 14 cents per cubic foot, the department to have the right to purchase the works at cost, and to continue the process at its own expense, paying, during the lifetime of the patent, a royalty of 4 cents per cubic foot of timber impregnated.

If at any time after the treatment of the 100,000 cubic feet of timber mentioned above the department is reasonably dissatisfied with the efficiency or desirableness of the process, it may annul the contract, and may require the company to vacate at their own expense and within a reasonable time.

If the department shall not elect to annul the contract or to purchase the works, it shall, from time to time, have impregnated 150,000 cubic feet additional (at the same price), after which it "may" purchase on the former terms.

The question of reasonable dissatisfaction shall be determined by a board of three constructors, before whom the company shall have notice and permission to appear and be heard.

Two years and two months after the signing of the above-mentioned contract, a board of three naval constructors was assembled at the navy-yard, Boston, and made a report (April 12, 1879) to the honorable Secretary of the Navy, in effect as follows: They saw a car-load of timber placed in a retort, or impregnating tank, and, after treatment, taken out.

They examined the timber, and found the process of impregnation had penetrated every part.

They also examined certain other timber of different kinds which had been submitted to the process, and found in every case the impregnation as perfect as in the first case (on which point they satisfied themselves by the aid of a microscope).

They also found that the timber bent as well as that which had not been treated. They further expressed the opinion that more timber should be preserved, designating live and white oak, yellow-pine timber, plank stock, and ships' knees as suitable. The report is signed by Constructors Webb, Wilson, and Boush.

The company was informed of the assembling of this board (by the Bureau of Construction), and permission was given to appear before it.

The papers handed to me contain no further allusion to the matter until December 3, 1880 (one year and eight months after the submission of the report of the first board), at which time a second board submitted a report to Mr. Secretary Thompson. The counsel for the company states (in his written argument) that about June 30, 1880, the company asked that this board might be appointed to determine the value of the works as they then stood. This board was composed of Naval Constructors Pook, Wilson, Hichborn, Fernald, and Boush; Surgeon Jerome Kidder, U. S. N., was a member, and apparently also acted as a chemical expert.

The board was ordered to examine the process and the timber impregnated, and to report the condition of the latter as to strength and durability. To report the original cost of the apparatus and its (then) value, and whether, in the judgment of the board, it would be for the interests of the department to purchase the works and continue the process. I infer that this was the board contemplated by article 7 of the contract. It was assembled at the request of the company. The report in substance was as follows: After numerous comparative tests, no difference was found between the strength of impregnated and unimpregnated timber.

It was thought that sufficient time had not elapsed to enable an accurate statement to be made as to the durability of the impregnated timber. This could best be ascertained after the wood had made one or more cruises.

The question of possible injury to the iron fastenings of a vessel (by electrolysis), owing to the presence of copper solution in the impregnated wood, was touched upon.

The board in this matter based its opinion upon "the information given by Dr. Kidder"; and assuming that the fastenings in the bottom of our ships would always be of copper, the conclusion was reached that no bad effects to the fastenings would ensue "where saline salt or sea-water would injure them."

The exact meaning of this part of the report is not clear to me, but the idea conveyed is that, assuming the bottom fastenings of a ship to be wholly of copper, the board did not consider that the iron fastenings that might be found above the water line would be materially injured by electrolysis.

The necessity of a preserving process was asserted, and a continuance of the one under examination advised, "until a better method is discovered."

The board also recommended the purchase of the works, giving the original cost as $38,891.95, and the "present" value not over two per cent. less.

There is an appendix to this report, in which Dr. Kidder answers several technical questions submitted to him by the board. His statements are in substance as follows: Two transverse sections of timber that had been treated were submitted to him.