AL LIBRARY FACILITY Biomed. WU in BSj'lf }»* ■ ' ','-'•■"■• + > ffl G 000 005 669 7 HBrai H3ftfii iffil IP MuMn nHnwaNtl BIN Hr $l$9£i SHI WkSKsWHS mGamfn WsatSSWa Hr mm Hi 91 [•i THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES ON THE DISCOVERY VULCANIZED CAOUTCHOUC ON THE DISCOVERY OF VULCANIZED CAOUTCHOUC AND THE I'ltlORITY ITS APPLICATION TO DENTAL PURPOSES BY THOMAS W. EVANS, MD. DDS. I'AIUS [MPRIMERIE SIMON RAQON El COMPAGN i , in i: d'erfurtd 180 7 QwrAeA WD MO £12.0 o\ THE DISCOVERY 1^7 VULCANIZED CAOUTCHOUC Jn 1804, I made a voyage to the United Stales, my native country, which at that period was desolated by civil war. There, upon the very scene of those important events which were taking place beneath my personal observation, I studied carefully the organisation of the military hospitals, and especially that of the Sanitary Commission, the history of which I proposed to myself to write in order to call the attention of the people of Europe to this admirable institution, so full of great and useful examples. Entirely devoted to these studies, undertaken with a philanthropic aim, it did not at first occur to me how great was the importance of a communication made me by Professor J. 1). White, of Philadelphia, one of those men who, by their talent, have helped greatly to ad- vance the science of dentistry in that country. The subject of this communication concerned me nearly, for it had reference to the. application of harden- ed, or vulcanized india-rubber to dental purposes : an — o — application thai I had made fifteen years before. Great was my surprise to learn thai this invention, which "was my own, had been given out as theirs by Messrs Cum- mings and Goodyear, who had taken out a patent for it, which they were intending to take advantage of, to the detriment of the profession generally. My surprise was great for the simple reason thai, previous to 1854,1 had made several pieces for Mr Goodyear, adapted to his own month, one of which pieces remains in my possession. On my return to my professional occupations in Paris, I considered it a duly to protest publicly against I he claims of those gentlemen, and to expose the facts ol I he case in a clear and precise manner, which would prove to the profession how ill-founded were these claims. With this aim, I addressed the following letter to the Association of Dentists of Massachusels, who had decided lo contest the validity of Mr Cumming's patent. Paris, Nov. 28th 1864. To the Members of the Massachusels Dental Associa- tion : Gentlemen, During my recent visit lo I he United Slates, Prof. .1. 1). While of Philadelphia put me in possession of a copy of the letter addressed by you to the Pennsylvania Association of Denial Surgeons in regard to certain Let- ters patent of Mr John A. Gunnnings of Boston, claiming the exclusive right lo use india-rubber for artificial pa- latesand for plates to serve as a base for artificial teeth. The short time I had at my command did not permit me, then, to give that attention to your communication which its importance demanded. As a member of the Pennsylva- nia Association , I felt imperatively called upon by your letter to communicate the knowledge of certain facts of which I am personally cognizant and which, I trust, will throw a clearer light upon the real worth of the claims now put forward. Sincerely desirous of seeing simple justice done to all parties, and of cooperating in the worthy object you have in view, I trust you will ex- cuse my speaking, on the present occasion, of matters somewhat personal to myself, and which, under other circumstances, I should have hesitated to mention. In America, where I had first studied my profession, I had been educated to the belief, then universally ac- cepted by the Dentists of the United States, that the best and most practical artificial pieces were those made with metallic plates and mineral teeth. I was struck, how- ever, on my arrival in Europe, with observing both in England and on the continent the very general use, in mechanical dentistry, of pieces made of bone, ivory or tooth of hippopotamus. From a knowledge of the long experience and eminent reputation of the leading European Dentists who adopted this practice, I could not but believe that this system must possess cer- tain decided and important advantages, to recommend it to such general favor. From personal observation, I was myself soon convinced that among the advanta- ges of bone, were particularly an elasticity of fibre closely analogous to that of the human bone-tissues, and a lighter specific gravity which rendered it less liable — 8 — to hurl the gums than ihe combination of metal and porcelain. Whilst these facts in its favor were placed beyond question, there were, at the same time, certain grave disadvantages no less observable, which seemed, in my judgement, to more than counterbalance the ap- parent advantages. The bone artificial work, through the action of the secretions of the mouth, changed color readily, soon decomposed, became very offen- sive, thus necessitating frequent renewal. From a careful study of the relative merits and demerits of the two systems, I was led to make a series of experiments with a view to discover some material which, combining the advantages of both, should offer a permanent resu- lt imc to iht 1 action of the fluids of the mouth, and, at the same time, possess the elasticity and lightness of the natural bone. One of the iirsl substances upon which 1 experimented was Caoutchouc. My efforts were particularly directed to discover how to modify its elasticity and how to change its color. In the early part of 1848, I devoted the leisure which the derangements of the French Revolution af- forded, to working out these problems, being then, and even now still, unaware whether any efforts were being made, at the time, by other parties towards their solu- tion. I had already previous proof that sulphur was a substance very little liable to change or decompose in the mouth. The knowledge of this fact, by natural induction, led me to think of combining it with caoutchouc. After trying many plans to work together the two substances, I hit upon the application of dry heal, and I succeeded in producing a material hard, black, and possessing Hie !» — elastic property of horn. In fact, one of the earlier Ori- ginal pieces of tin 1 substance thus discovered I put away in a drawer of my cabinet, and upon the paper which envelopped it, I wrote the following words: "Tried to find ivory, succeeded in making ebony. " Subsequently, by employing successively moist heat, and then steam, 1 obtained still more satisfactory results. The speci- mens of the substance finally produced were in every respect identical with the vulcanized india-rubber now in use, with the exception of the color, and this last deficiency I sought to modify by employing various color- ing materials in the composition. From the year 1848 forward, I continued to make from time to time new experiments upon caoutchouc. From a previous experience, however, with another preparation which had promised at first most excellent results which the lapse of time did not confirm*, I used the utmost caution in adopting the hardened caoutchouc into my practice, as I wished first to assure myself of its durability and practical value. In 1851, my attention was drawn to the fact that Mr Charles Goodyear S r , had t;tken out patents in the United Slates for the discovery of a new substance which, from the description given, seemed to resemble what I had myself independently discovered. Towards theclose of the same year, or early in 1852, Mr Charles Morcj applied for letters-patent in France for the hard india- * Tin' substance in which I allude, white, malleable and of an easj applica- tion, seemed in possess all the qualities requisite to make ■■< perfeel tilling. In pre sence of these apparenl advantages, [published iri the London iMncet some notice ol' ii. But upon longer experience and time, in a second notice, 1 presented these inconveniences and objected in its use, — Id rubber, and as Mr Goodyear had nof taken the precaution to secure his own patents in Franco, the application of Mr Morey was favourably entertained, and a patent was awarded him by the French government. 1 had previously fully acquainted Mr Morey with what I had myself succeeded in doing, and he was candid enough, then, to admit that, so far as he was able to know, my experiments had been made in advance of the date of Mr Goodyear's patent in the United States. Mr Goodyear, in coming to Paris, made an arrange- ment, I believe, with Mr Morey. Mr Goodyear arrived at the Hotel de Douvres, rue de la Paix, Paris, after the close of the London Exhibition of 1854. The next morning after his arrival, 1 called upon him and I had a full and free conversation with him on the subjec of caoutchouc, on which occasion 1 men- tioned in detail my previous experiments and my hopes from the use of caoutchouc for dental purposes. 1 have a most distinct and vivid remembrance of one remark in particular which he made in reply : "Here, again, is a new application which I never thought of." He urged me to make him a set of teeth with caoutchouc as the base, and 1 did make him not only one, but several pieces for his month, one of which I have still in my possession to the presenl day, and which is, I think, quite as »ood, as regards the material, as 1 have seen since. After hearing the account of my own experiments, heexpressed the wish that 1 would take no steps to contest his patents for hard india-rubber, and byway of consideration for my making no opposition to his claims, he offered of his own live will to give me the exclusive right to his patent — 11 — for the entire contirien I oi Europe, he wishing to retain for himself all of the United States and England. To this oiler 1 made an instant and decided refusal, basing my re- fusal on the ground that I was opposed upon principle to any patents within the domain of professional science. I, also, look occasion to state to him that 1 should unhe- sitatingly claim at all limes what I felt to be my right, and that I should continue to use and should urge others to use caoutchouc as a base for artificial teeth, without paying- any regard to any patents. And this principle 1 have constantly maintained. Subsequent to the first visit, of Mr Ch. Goodyear S r , his son, Mr Ch. Goodyear Jun 1 , came to Paris, lie called upon me on several occasions, and I spent a good deal of time in freely acquainting him with the various processes. 1 had employed in making my moulds, in manipulating and moulding the substance, in adjusting the teeth, etc. In May 1855, he took out a patent for the application of caoutchouc as a base for artificial teeth. I learned this fact with surprise, as I had strongly expressed to him my desire that this application of caoutchouc should not be patented. My opinion was clear, and still remains un- changed, that. I his patent, not being for an original in- vention, was certainly not entitled to stand good, and that the members of the dental profession had, therefore", an indisputable right to the unrestricted use of hard caou- tchouc in the operations of mechanical dentistry. In 1858, Mr Putnam of New York called upon me, and informed me that he bad brought out with him spe- cimens of an improvement in caoutchouc for which he ask- ed a consideration. He exhibited several pieces of arliti- - 12 — cial workin caoutchouc, which, J noticed, had stamped upon them the words: "Goodyear's Patent." He was under the impression thai he was showing something en- tirely new in Europe. To undeceive him, I produced, to his astonishment, sonic pieces of my own, which had been made several years before, and which bore a close and very striking resemblance to those which he had shown me. I staled to him frankly that I had found that in manipulating the hardened caoutchouc there was an uncertainty of result, as its consistency could not be al- ways depended upon, the substance being sometimes more porous, at other times more brittle. He gave me assurances that he could give me certain information as to the mode of baking- and of manipulating- the ma- terial, which would obviate the recurrence of these difficulties and which could guarantee uniform re- sults. He spent several days in making experiments. But he failed to obtain any thing better, or any greater degree of uniformity than I had myself. The year follow- ing he came abroad again with a new machine for vul- canizing, which appeared to possess advantages over that which I had then in use. I, therefore, purchased one of him, as my wish was to obtain every improvement thai appeared to offer any advantages. Within a few years past, as is well known, many im- provements have been made in vulcanizing machines and in the use of vulcanite. Bui the members of the dental profession have been uniformly desirous to have the li- berty to use these improvements thrown open to all. Unite recently, some members of the leading dentists, both in England and France, have concurred in a declaration — 13 — to theeTfect thai the introduction of vnleanite into me- chanical dentistry has been of great advantage to the pro- fession and of immense beneflt lo humanity, and that its use should be therefore left untrammelled by any patent rights whatever. In conclusion, Gentlemen, I need scarcely add that I cordially wish success lo the efforts put forth by your Association and in which 1 doubt not the entire dental profession of America will heartily concur. I have the honor to be, Gentlemen, with high regard. Your most obedient servant, Thomas W. Evans. MD. DDS. The letters in which the Members of the Association acknowledged the receipt of this notice left me no doubt .is to the importance that the Dentists of America attached to the question. The facts which I commu- nicated to them seemed in their opinion decisive. Here; are those letters; the reader may judge with knowledge of the cause. 616, Washington Si. Boston, January 14th, 1865. ToTho W. Evans MD. DDDS. Dear Sir, Yours of the 14lh November was duly received. I also received the Communication adressed to the "■ Massachusets Dental Association. " The first I read l«> the Society at its last monthly meet- — It — ing. The other, which was not Lhen received, will be read al our next meet inn. The paper addressed to llieSociely has been read by the eminent Counsel, Hon. Joel Giles, having in charge the defense of the suits commenced by John A. Cummings. He was pleased to say that he deemed it a paper of greal importance, and advised that it be laid before the Committee ofGongress having in charge the application for a renewal of the Goodyear patent. 1 write at this time merely to thank you in behalf of the Mass. Dental Association, and for myself personally, for your great kindness in making so important a com- munication, settling, as it seems to us, the question of priority of discovery of the application of rubber to dental purposes. After our next monthly meeting, I have no doubt you will receive an authoritative communication from the M. I). A. Jn the mean time, I remain, dear sir, \our very humble servant E.C. Rolfe, M. D. Cor. Sec. Mass. Dental Association Boston, Mass. U, S. 616, Washington St. Boston, May lOih, 1865 To Tho s \Y. Evans, MI). DDS. Dear Sir, 1 have the honor to transmit to you the following communication : " Dr. Rolfe. cl Hoar Sir, tw At a meeting- of the Mass. Dental Association held on Feb. 20th, 1 865, itwas voted : that the thanks of this Asso- ciation he presented to Dr. Tho s W. Evans, of Paris, France, for his very interesting and valuable communi- cation : and that the notice thereof be certified by the Officers of the Association. "Also voted unanimously: that D. Evans of Paris be constituted an Honorary Member of this Association. "Respectfully yours, etc. " Tno s H. Chandler, Secretary. " "Also at a meeting held March Olh, it was voted: that the thanks of the Association he presented to Dr Evans for his gift of his History of the Sanitary Commission. ' ' Yours, etc. tw Tiio 5 II. Chandler, Sec. " A true copy : E. C. Rolfe, M. D. Corresponding Secretary Mass. Dental Association. About the same time, 1 received from Mr Shaw, den- tist in Manchester, a letter which proved how much I was righl in having addressed my communication to the Massachusets Dental Association. Other American den- tists who were not yel aware of my letter to that Associa- tion, had addressed to Mr Shaw, in view of obtaining from this gentleman information concerning the inven- 16 lion of vulcanite for dental purposes; and Mr Shaw wrote to mi' the following letter "• M.mrh.-lrr. Dec. Uil.h, J 864 kt l»r Evans. "Sir : "An American Dentist, Dr Cutter, of Boston, Mass., wrote to me a short time since, lo ask if I could give him any information ahoul the nsr. of vulcanite lor denial purposes previous lo its introduction here by Putnam in 1857, as il had been tried by a person who professed lo have a patent on the idea of using vulcanite lo mount teeth on. 1 have written to MessrsC. Ash, Sons, of Lon- don For information, and they say that they understand you made a piece on hard rubber as early as 1 852. This would be all, I think, my correspondent would require lo upset the pretended patent. "My correspondent is a stranger to me, and 1 only in- terest myself because ofthe Society of Dentists in Boston, who is composed of the most respectable gentlemen there, and are the real dependents. "Now, would il be asking too much of you to fell me if yon did make a piece or even allempl a piece, on vulcanite or hard rubber before 1855 or 1856, and il so, in what year, and give me any other information you may have in your possession, bearing on this subject V By so doing, you will confer on me a personal favour, and more especially do a favour lo our American dental Brethren who are constantly pertened aboul patents in n manner Dentists in Europe know nothing. " Believe me your obedient servant, " S. Pashut Shaw, li Dr Evans. "Paris". The application of vulcanized india-rubber in the science of dentistry has been so generally appreciated, and has rendered such good services to all classes of society, that we may admit, without any presumption on our part, that all who have read the preceeding pages will have be- come interested in the question of priority of claim which we are endeavouring to establish. Let me then be permit- led to recapitulate the facts, and set forth in a few lines llie stale of the question down to the present time. As early as the year 1848, I had succeeded by my own experiments in transforming- india-rubber, com- bined with sulphur, into a substance identical with that which has since been called hardened , or vulca- nized india-rubber. These experiments had been un- dertaken entirely with a view to employ this substance in my surgical operations and in dental apparatus; and previous to 1854, I placed, as I have said, in the month of Mr Charles Goodyear, Senior, a piece made of vulca- nized rubber, a short lime after, and before any patent had been taken out, I explained to Mr Goodyear son, how I prepared the casts and the setting of t lie teeth in the caoutchouc, and Mr Goodyear expressed to me frankly — IS — and without dissimulation the astonishment, I may say llie admiration which he fell al my invention. Now, twelve years, later, 1 learnt with a feeling of surprise thai Mr Cummings pretented to have made ihis disco- very himself, and to have been the first to have made this invention which I had shewn to Mr Goodyear, which I had conceived and applied, and freely given to the pu- blic, happy to have been the author of an invention which was welcomed eagerly by many of the profes- sion, a large number of whom were ignorant of its ori- gin, — an invention which, I can say from conviction, has produced a remarkable revolution in the science of dentistry. A lirm opposer of all special protection by patents in the appliances which concern the arts and sciences, I had declined the propositions which were made me to ake advantage of my invention, and had more especially declined those of Mr Goodyear. Hence I could consent to leave my brother-dentists, in whatever country, free to profit by my invention without any sort of restriction; I could even, in the inte- rest of humanity, wish they might do so; but that which I could not tolerate Without protesting against it, was that more than twelve years after having thus given up my invention to the public, a man should come not merely to attribute to himself the merits of what he had neither found out the first, nor applied, but that he should have dared to do what the actual inventor had considered as prejudicial to the dignity of the profession and to lilt; interests of humanity, that is to say, levy a lax on all those practitioners who employed (or the — 19 — service of their patients an invention destined to relieve human suffering. To protest against lliis, and establish the fads in their true light, I addressed to the Society of Dentists al Boston ihe letter which lias been read, and which, at the same time, I published in a pamphlet at Paris in french. I thought that in the face of a like declaration, I lie question in dispute was decided in the judgement of all, and that the strange claims of Messrs Cnmmings and Goodyear would be completely negatived. The dentists of the United States and the lawyers whom they had consulted, were of the same opinion. But we had deceived ourselves on this point, and in 1864 Mr Cummings obtained his patent notwithstand- ing the protestations of a great number of competenl persons. But the opinion of the public was awakened by this patent being- granted; a Society was organised with a view to bring- the question before an higher court, and a public subscription was opened at Philadelphia, and elsewhere, the products of which were to be devoted to the costs of the law suit. It was al this time that the following letter was ad- dressed to me by the Society of Dentists of Maryland : " Baltimore (Md.), December 5tb, 18GG, "ToDr Tho s Evans. "Dear Sir, "We are desirous to obtain from von the following information. — -2\) — '•First. At what lime you made the Grsl set of teeth on vulcanite? (State exacl date if possible.) " Second. Did you make a set of teeth on vulcanite for Goodyear? If so, at what dale? "Please certify to your replies lo I lie above question's in such legal form as will make them available before the courts in this country. "It is understood in tin's country that you are the real inventor of the adaptation of teeth lo vulcanite; but a man by the name of Gummings (unknown lo the profes- sion here) has claimed to be the original inventor in 1854, but whose patent is dated 1864, and under which a tariff of 4 1 is now sought lobe imposed upon the profes- sion for every piece of work containing- six. teeth and under, and & w 2, 50 for each piece containing over thai number. This is regarded as a manifest fraud both upon the profession and the community, and a very ge- neral determination prevails to resist it. Suits have been brought against parlies here and elsewhere, and we desire lo obtain such information* as will furnish us the dale In successfully resist these pretentions lo exclusive privilege. We have information that you made a sel for Goodyear, and I think it was published in some of the periodicals, probably the "American Journal of Science." We will be greatly your debtor for any light you can throw upon ibis subject. •' Very truly, eic. "S. II. Williams. il Cor. Sec. .1. Mankind State Dental Society.'' — 21 — It is in response lo the proceeding letter, in the inte- rest of the profession and to bring fully lo light and plaee beyond a doubt my right lo the priority of the ap- plication of vulcanized rubber lo dental purposes that 1 published the documents which have just been read, and that I add thereto, as further testimony, the legal declaration which follows, as well as the attestation of Madame Morey, the wife of Mr Morey whom I have mentioned in my letter lo the Dentists Association of Massachusetts. UNITED STATES CONSULATE I'aius, Empire o! France. Be it known ihal on lliis twenty-third day of January, one thousand eight hundred and sixty-seven, before me John G. Nicolay, Consul of the United Slates of America at Paris, in the empire of France, personally appeared Dr Thomas W.Evans, who being duly sworn, dolh depose and say as follows : I, Thomas W. Evans, dentist of Ihe United Stales of America, residing in Paris, surgeon lo ihe Emperor of i lie French, officer of the Legion of Honor, etc, etc., do hereby declare : isl that 1 composed as early as ihe year eighteen hundred and forty-eight (1848) the substance now called Vulcanite or Hard-rubber. "lint thai previous to the year eighteen hundred and fifty four (1854) [made with vulcanized rubber artificial pieces for the mouth of Mr Charles Goodyear, senior. 7)nl thai 1 still have in my possession one of the pieees which was destined for ilic mouthof Mr Charles Goodyear Sen'. bth that the substance composing that piece is iden- tical with thai called Hard-rubber or Vulcanite, now used in the dental profession. .">//< thai Messrs Morey, widow of Charles Mbrey, lias declared to me thai she was present upon many of the occasions when I spoke to her husband of my inventions and applications of caoutchouc and she was cognizant of the facts which 1 have slated, Thomas W. Evans, MD. DDS. Subscribed and sworn to before me this twenty-third da\ of January, \. n. 1807. In witness whereof] have hereunto set my hand and consular seal the day and year above written. (Signed) : John G. Nicolay, U. S. Consul. UNITED STATES CONSULATE I' u;i^, Empire of France, He itjmown thai on the twenty-sixth da\ of January, one thousand eighl hundred and sixty-seven, before mc John G. Nicolay, Consul of the United Slales of America, al Paris, in llie Empire of France, personally appeared Messrs Anna Chadbourne Morey, who, being duly sworn, dolh depose and declare as follows : I, Anna Chadbourne Morey, widow of Charles Morey, do hereby depose and declare that I was often present when Dr Thomas W. Evans spoke to my husband of his (Dr Evans) inventions and applications of vulcanized caoutchouc in the construction of artificial pieces, and thai 1 am cognizant of many of the facts establishing that Dr Thomas W. Evans applied caoutchouc to denial pur- poses, previous to the year eighteen hundred and fifty- four (1854). Anna Chadbourne Morey. Subscribed and sworn l<> before me this twenty-six lb day of January, a. d. 1807. Jn witness whereof 1 have hereunto set my hand and consular seal I he day and year above written. (Signed) : John G. Nicolay. U. S. Consul. I'AUIs. — PIUMTED MM O.N r.A