T H E J O U R N A L OF I N D U S T R I A L A N D EA’GINEERING C H E M I S T R Y . earliest engineering experience as the chemist and technical director of a Gold Mining Company in Nicaragua, though it had been of great service in developing his power and self-confidence in the application of science to engineering, yet had given him little reputation. I n the new position his ability and energy were soon recognized. He became, in 1883, chemist of the Geological Survey of Ohio, contributing in addition to his chemical reports valuable chapters on the iron industry and on the differentiation of the coal seams of the state by novel methods. His grasp of these subjects was so masterly that he became a national authority on fuels and fuel-testing, and for the past eight years has been chief chemist or consulting expert of the Technologic Branch of the United States Geological Survey, now the Bureau of Mines. Upon the College of Engineering, Professor Lord has left an enduring mark. As its first Dean, beginning in 1896, he carried it through its formative period, and left it with policies and ideals well crystallized. His sane and practical mind rejected instantly everything that savored of show or pretense. As in his engineering, so every educational plan must rest upon a solid foundation. His constant struggle was t o ground his students thoroughly-well assured t h a t upon such a foundation they would erect a secure superstructure. His teaching was a constant appeal to the reason, and to the constructive imagination. To see him with a class attack a problem new to both was a rare experience. Combined with his power and inspiration as a teacher, was his pre-eminent ability as an investigator. The training of the chemical laboratory, where everything must be accounted for, gave to his naturally incisive thinking processes a precision and analytical power most unusual. No man could with more unerring certainty strip a complicated problem of its
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disguises and lay bare its fundamental principles. S o field of science upon which he touched failed to profit in some enduring way from his ever active mind. S o man could associate with him in any capacity without admiring him; his large mind and generous spirit had no room for anything little or sordid. Creditable, useful, even brilliant, as many of his contributions to science and engineering have been, his influence on his students and on his colleagues is the signal proof of his greatness. T o the very last he was a man of diversified interests and continually entered upon new pursuits with characteristic enthusiasm. Professor Lord was a man of marked intellectual vigor. His mind was no less judicial than analytical. He thought clearly and spoke with logical precision. In action he was prompt, decided and fcarless. His moral convictions rested upon reason rather than upon authority or tradition. With the reserve of a gentleman who permitted no undue familiarity, he yet remained essentially democratic, and no one felt humbled in his presence. Honesty was fearless before him. To those who won his confidence, he was a loyal friend and a wise counsellor. In the death of Professor Lord this Faculty mourns the loss, not merely of their colleague of longest unbroken service, but of the brilliant man of science, the incisive and powerful teacher, the keen yet broadminded counsellor, the vigilant and strong supporter of the university, the loyal citizen, delightful companion and generous friend, the man of rare quality, originality and broad interest, whose place in the hearts of those who knew him intimately, can never S. C. DERBY, be filled. WILLI.4M R. L A Z E N B Y , EDWARD ORTON,J R .
NOTES AND CORRESPONDENCE. CONDENSATION PRODUCTS OF PHENOLS AND FORMALDE HYDE.
To the Editor of the Journal of Industrial and E n g i neering Chemistry. SIR: I n the June number, 1911,of THISJ O U R N A L , reference is made to phenol-formaldehyde condensation products invented by Mr. Aylsworth. I am unable to find in the chemical literature any publication of Mr. Aylsworth relating to this subject, except a Belgian patent application dated February I I , 191I , No. 232,899, claiming International Convention Priority of one year, in accordance with a corresponding United States patent which has been applied for. Belgium is one of the countries where patents are allowed without any preliminary examination whatever as t o novelty, and where, furthermore, no restriction is put on the claims, nor the text of the patent,
the granting of the latter being a mere formality which places the claims of the applicant on record. For persons who are not acquainted with the technical and chemical side of the subject, the long text of XIr. Aylsworth’s Belgian patent is undoubtedly very complicated and liable to mislead. But when we come t o the question of novelty, we find that the principal claim has for object the preparation of a hard, infusible condensation product b y adding formaldehyde or its equivalent t o a fusible phenol resin. I t so happens that this reaction was clearly disclosed in THIS J O U R N A L about one year before the Aylsworth patent was filed: (See Jo-tcrnal of I n dustrial and Engineering Chemistry, Vol. I, No. 8, August, 1909,L. H. Baekeland, “ O n Soluble, Fusible Resinous Condensation Products of Phenols and Formaldehyde,” read May 14, 1909), from which I quote :
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T H E J O U R N A L OF I-YDUSTRIAL A N D E,VGISEERISG C H E M I S T R Y .
“ I n whatever way novolak be prepared, its properties are very distinct from those of bakelite and i t cannot be transformed into the latter by simply heating. But I have found that b y heating novolak in sealed tubes a t 180’ C . , under pressure with an excess of formaldehyde solution or any of the polymers of formaldehyde or other compounds which can generate formaldehyde, an infusible, insoluble mass is obtained that does no longer soften under the action of heat, as is the case for saliretin products, but which has all the characteristics of bakelite C.” The term novolak was the generic proposed name to designate all fusible soluble condensation products of phenols and formaldehyde of the type designated by Aylsmorth as “phenol resin” or “ resine phenique.” Furthermore. in patents granted t o Eaekeland in France (first add-ition to Patent 386,627, S o . 11,628, filed January 2 2 , 1909) and in Belgium (No.213,576, published February I j , 1909) the invention is disclosed as follows: “L’inventeur a trouve egalement que, au lieu de partir ‘des phenols et de la formaldehyde, on peut commencer indirectement avec l’emploi d’un phenolalcool ou ses equivalents, chauffant sept molecules de ce dernier avec au moins une molecule de CH,O, ou une quantite equivalente de n’importe quelle substance contenant de la formaldehyde, OIL capable de liberer cette derniere.” The “phenol resin ” of the Aylsworth specification answers all the descriptions and all the properties published by Blumer. (See Eng. patent June j , 1902, No. 12,880) and DeLaire (see French patent June 8, 1906, No. 361,539) and the description set forth in Baekeland’s prior publication in T H I SJ O C R N A L . ~ It is true that in the Aylsworth Belgian patent it is claimed t h a t the fusible phenol resin has a molecular weight smaller than what I assigned t o these products. On the other hand, it is stated that the molecular weight proposed b y Mr. Aylsworth is based on ‘‘ quantitative synthesis,” whatever t h a t may mean. I t should be pointed out t h a t we have t o deal here with substances which are amorphous, non-crystalline, non-volatile, and can not be purified by the usual ways. Furthermore, in any of these reactions, several substances are liable to be produced a t the same time. These substances can form solid solutions one with another, or with any excess of the reacting materials employed. Under the conditions, so-called “ quantitative synthesis” would hardly be accepted in any scientific controversy, and specially not for determining the molecular weight. The same can be said of any attempt to apply the other usual physical methods for the determination of molecular weights t o similar substances unless the latter have been submitted t o thoroughly careful purification. To omit this precaution would bring about such absurd results t h a t i t would only depend upon the operator to get almost any desired molecular weight by increasing for instance the amount of free phenol. 1 L O C . ctt.
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But the fact is undeniable that the physical and general chemical properties of the phenol resin described by Mr. Aylsworth correspond minutely t o every prior description of these so-called fusible soluble resinous condensation products. The Baekeland Belgian and French patents, as well as the corresponding Hungarian patent, mention the use of a phenol-alcohol, or its equivalents, heated in presence of formaldehyde or its equivalents. The phenol-resin described by hIr. Aylsworth is an equivalent of phenol-alcohol, as conclusively shown by DeLaire (see Eng. patent No. 1 5 , j 1 7 , 1 9 0 j , and D. R . P. No.189,262, 1 9 0 j ) . The dishydration of phenol-alcohol produces fusible phenol-resins, specially if a slight excess of phenol is present. In the process described in Mr. Aylsworth’s patent, hexamethylentetramin is used instead of formaldehyde, but this hexamethylentetramin is a well-known equivalent for formaldehyde, or better for a mixture of formaldehyde and ammonia. Whenever ammonia and formaldehyde are mixed together, hexamethylentetramin is produced forthwith. So practically, whether you make a mixture of phenol and add formaldehyde, and then add ammonia, or whether you add ammonia to the formaldehyde first, or to the phenol first, and then afterwards add the formaldehyde, the mixture behaves entirely as if a n equivalent amount of hexamethylentetramin were used. This fact is in direct contradiction with the statement contained in Mr. Aylsworth’s description, that no accelerating or condensing agent is used ; indeed, the formaldehyde and the condensing agent, ammonia, are used here a t the same time. In the Baekeland U. S. patent No. 942,809, ammonia is used as an accelerating or condensing agent, and it is expressly stated t h a t the addition of the ammonia can be made a t any stage of the reaction. As a further contradiction to the claim in the Aylsworth patent that no condensing agents are used there, i t should be pointed out that a little further in the text, he mentions the use of amids of weak organic acids. But the value of these products as condensing agents has been disclosed in Baekeland’s U. S.Pat. S o . 942,809, in the text whereof i t is stated that ammonia can be replaced by amines and amids of weak acids (see also Eng. P a t . , Baekeland, No. 21,566, 1908). Special stress is laid in the Aylsworth patent on the addition of substances which make, with the final product, a so-called solid solution, thereby increasing plasticity. This claim t o novelty is also anticipated in some of my pending patents which have been filed a t a date decidedly prior t o Mr. Aylsworth’s applications. A special reference is made t o the fact t h a t in the Aylsworth process, the use of pressure can be dispensed with. I n most of the processes described a n d patented b y me, the use of pressure is-only resorted t o in special conditions in order t o accelerate or expedite the process, but in many cases, is entirely dispensed with. Indeed, the use of small quantities of basic or alkaline condensing agents, which I was t h e
T H E J O U R N A L OF I N D U S T R l A L A N D ECNGINEERIA-G CHEAWISTRY. first t o publish and patent, enables t o obtain rapid hardening a t relatively moderate temperatures, which can be rapidly increased without the intervention of pressure. Nevertheless the process will be quicker and much more practical if a t once the maximum temperature be applied and then, of course, pressure shows its strikingly favorable action. This pressure can then be applied in a hot hydraulic press or in a bakelizer, or any convenient way. L. H. BAEKELAND. Y O N K E R S - O N - ~ I U D S OJNu,n e
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1911.
GEMS T H A T RESEMBLE T H E DIAMOND.
I n spite of many seductive advertisements there is no gem t h a t “looks j u s t Like a diamond.” Nor should we expect t o find one, for, while two different substances may have a number of properties in common yet a study of all the properties of each will show many which differ. Still there are a number of gems which possess t o a considerable degree some of the properties of the diamond and when well cut these gems can deceive and frequently have deceived those not expert in the determination of precious stones. I n times past such gems have even passed current as diamonds before the scrutiny of experts, for until the general spread of science, such tests as those of specific gravity, refraction, etc., were not applied, and many colorless zircons, topazes and sapphires probably passed as rather inferior diamonds. It is even claimed t h a t the Braganza, a mammoth uncut gem among the Portuguese crown jewels, is merely a fine specimen of colorless Brazilian topaz, yet i t has been listed for years among the world’s greatest diamonds. Among the gems which may be regarded as so closely resembling diamond as t o be likely t o deceive the inexpert, I will list and briefly discuss the following: First, the colorless or pale zircon, sometimes called in the trade, the jargoon; Second, the colorless sapphire ; Third, the colorless true topaz ; Fourth, the colorless beryl; Fifth, colorless phenacite; Sixth, colorless quartz. These and a few other and rarer colorless gems constitute the list of gems t h a t resemble the diamond. I may say a t this point that none of them resemble the diamond t o the casual glance so closely as does the very brilliant lead glass used in making the so-called “ p a s t e ” or “strass” imitations SO widely advertised and sold under various fictitious titles in many cities. This artificial material possesses a very high refractive index and is capable of separating the various colors of the spectrum so widely t h a t i t affords a brilliancy and “ p l a y ” of colors t h a t nothing but the diamond can equal. I t is, however, deficient in hardness, being easily attacked by a file and consequently i t does not long resist dufling and scratching from wear and hence does not hold its brilliancy. I t is also easily attacked chemically b y a number of things, with which it is likely to come in contact in wear and thus be still further dull. I n many of the imitation diamonds the
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tendency to scratch is partially prevented by using a thin slice of some hard gem material for the upper surface, making in other words a so-called “diamond doublet.” This artificial gem has no real diamond about it of course, although formerly a few real diamond doublets were made in which the upper half of the stone was made of real diamond and the lower half of some less costly white gem, the two being joined a t the girdle b y means of gum mastic or other transparent cement. The modern diamond doublet usually has an upper surface made of a very thin slice of garnet, covering usually only the table, as the part subject t o greatest wear. The garnet used is pale in color and so thin is the slice t h a t hardly any color is visible. The remainder of the “stone” is entirely of lead glass. Some of these “works of a r t ” are certainly very beautiful and a t a reasonable distance they would probably puzzle a n expert. While none of the genuine gems I have listed quite approaches the “paste diamond” in play of colors, many of them are nearly as brilliant in the lively play of white light which they afford when cut in a manner suited to such material, which cutting, b y the way, should not be just like t h a t most suited t o the diamond. I n regard t o the order of precedence among them, I should put the colorless zircon first. This gem possesses adamantine luster in a high degree, t h a t is, the amount of light reflected from its t o p surfaces, when properly inclined t o the light, approaches closely t o the amount reflected b y a genuine diamond surface. This effect must not be confused with the brilliancy of the flashes of light reflected from the interior rear surfaces of the stone. That is another matter. This adamantine luster gives what the French call Cclat t o the zircon. It is snappy, cold and glittering in its luster. So closely does it resemble diamond in this respect t h a t I was able t o deceive a diamond cutter in one of the best establishments in this country b y a brown zircon which I wore in my scarf this summer. He referred t o it as my “brown diamond” although he was not above four feet away and looking squarely a t it. Of course in a stone of positive color, no large amount of prismatic “ p l a y ” is possible or expected, and so the lack of it in my brown zircon was not felt. The cutter would doubtless have detected the difference in a colorless zircon but one not so expert might not. Of course, in hardness, in specific gravity and in refraction, the zircon is not like the diamond. It is much softer being only 7 . j as against I O in hardness b y Moh’s scale; its specific gravity is 4.4-4.7 as against 3.5-3.6 for diamond; and i t is doubly refracting while diamond is singly refracting. It could thus be readily distinguished b y any one who understood the application of the tests for the above properties. After the zircon in order of excellency I would place the white sapphire. Its index of refraction is higher than t h a t of any of the other gems in m y list except the zircon, and its great hardness renders i t capable of taking and holding a polish almost equal to t h a t of the diamond. I t does not possess the adamantine luster, however, I t s luster is probably best defined
