TS 
 
 -NRLF 
 
On the Making 
 of Silk Purses 
 from Sows' Ears 
 
On the Making 
 of Silk Purses 
 from Sows' Ears 
 
 Contribution to 
 Philosophy 
 
 Arthur D. Little, Inc. 
 
 n 
 
 Chemists . Engineers . ^Managers 
 
 Cambridge, Massachusetts 
 
 1921 
 
On the Making of Silk 
 Purses from Sows' Ears 
 
 "You Can't Make a Silk Purse 
 of a Sow's Ear " 
 
 EVER since somebody said it first 
 and that was centuries ago it has 
 been repeated with gusto. It has 
 been quoted principally for purposes of dis- 
 couragement. Whosoever has striven for 
 betterment, to make something desired out 
 of that which is held in low esteem, has had 
 to feel the cutting edge of this hoary old saw. 
 It has been bothering us for all the years that 
 we have had a chemical conscience. We have 
 felt that it is not true, in spite of tradition 
 and public opinion and the so-called wisdom 
 of the ages. We resolved some day to prove 
 that it was false, and we have done so. We 
 have made a silk purse of a sow's ear. 
 
 The first question to answer was: What 
 does the silkworm do how does it make 
 silk? 
 
 It eats mulberry leaves and produces 
 threads by a chemical process by a very 
 intricate chemical process. 
 
 If we watch it carefully we shall have 
 abundant occasion to marvel; but science 
 teaches us that to marvel is but the prelim- 
 inary phase of observation. We cannot at- 
 tain results by marveling alone; so closer 
 study reveals the fact, long known to en- 
 tomologists, that the silkworm has in its 
 head two very fine ducts, or openings, that 
 have a common external orifice. 
 
 PAGE ONE 
 
 458699 
 
OK tks Making of 
 from Sows' Ears 
 
 When the time comes for it to make the 
 Great Change, to transform itself from a 
 gluttonous worm into a winged moth, to 
 cease its gross existence as a creeping thing 
 and to enter into an aerial life, to sip honey 
 and to make love, it requires an envelope for 
 hiding, for a dark and secret place, according 
 to the command of Nature. 
 
 From certain glands at the back of its 
 head it ejects two minute threads of a viscous 
 liquid which become coated with another 
 secretion flowing from two other convenient 
 glands, and these two little streams are thus 
 cemented to a double strand. 
 
 On reaching the air the thread coagulates 
 and becomes a firm, continuous filament of 
 silk. With this thread the caterpillar makes 
 its cocoon, seals it up, and straightway goes 
 into its mystic lepidopteran sleep. When the 
 day of awakening is at hand the young moth 
 softens the end of its cocoon by wetting it 
 with an alkaline solution from its head, and 
 so forces its way out. Then, ho, for moonlit 
 gardens and a short life full of adventure, of 
 cosmic urge, and of strange experiences! 
 
 The Chinese say it was a lovely and gifted 
 queen who was the mother of the silk in- 
 dustry, and industry whether out of the 
 mind of the lovely queen or that of one of 
 her followers, we do not pretend to know 
 has discovered that the moth destroys the 
 continuity of the fibre by forcing its way out. 
 Therefore industry foreordains the moths to 
 death before they are born, if they are to con- 
 tribute silk, by steaming them or freezing 
 them or submitting them to dry heat. 
 
 PAGE TWO 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 The cocoon consists of a loosely woven 
 outer layer called the "floss," which envelops 
 the inner part called the "pod," which in turn 
 encloses the sleeping, changing worm and 
 finally the unborn moth. About one sixth of 
 the cocoon is available for fibre, of which 
 about one half can be unwound and reeled, 
 while the remainder, from the floss and inner 
 pod, is combed or carded and spun. 
 
 Our particular interest was in the silk- 
 worm as a chemist. It emits a viscous liquid 
 which, on reaching the air, turns into a silk 
 thread. This viscous liquid is very like 
 glue it hardens in the air like it and is 
 becousined to it, chemically. This chemical 
 cousinship is an important point. 
 
 Again, the sow's ear being chiefly gristle 
 and skin, we have in it a natural raw ma- 
 terial for glue. The first step, then, was to 
 treat some glue so that it would behave as 
 much as possible like the viscous liquid 
 which the silkworm exudes as the last deed 
 of its vermiforous life. This was done, and 
 after some experiments we adopted the 
 method which we shall soon describe. 
 
 Next we wrote to Messrs. Wilson & Com- 
 pany, of Chicago, who, it is needless to say, 
 had a sow. Indeed they had many of them 
 so many that they cut off and placed at our 
 disposal no less than one hundred pounds of 
 ears, with an affidavit that they were, as 
 represented, the ears of departed sows. 
 
 Being thus abundantly provided with the 
 raw material for our silk purse, we prevailed 
 
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 PAGE THREE 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 upon Messrs. Wilson & Company to under- 
 take the extraction of glue from these iden- 
 tical ears. This was done in their Research 
 Laboratory under the personal and scientific 
 
 LABORATORIES. 
 
 *"''" March 18th, 191. 
 
 STATE Of ILLINOIS) -c 
 COOTTY Of COOK ) 
 
 c^ being duly sworn deposes and Bays that he Is employ- 
 ed by WirSOH & COMPAHY, Inc., Chicago, Illinois as Vt t, ^-^t^j V'^^* 
 and that he supervised the; manufacture and packing of ten pounds of gela- 
 tine shipped to Arthur D. little, Inc., Cambridge, llaee., on the lth day 
 of March, by parcel post (Insurance Bo. G 441424) and that said gelatine 
 was manufactured wholly from sows' ears. 
 
 And further deponeth and sayeth r.ot, 
 
 Signed' 
 
 Subscribed and sworn to 
 before me this 17th day 
 of March - 1 9 1 
 
 ** 
 
 ,] Rotary Publi 
 
 control of their chemist, Mr. Frank R. John- 
 son, to whom we here take pleasure in making 
 our acknowledgments. The glue, with Mr. 
 Johnson's identifying affidavit, was for- 
 warded to us under seal, and we thereupon 
 proceeded with our work of transformation. 
 
 Undoubtedly sows' ears lose somewhat of 
 their individuality when handled in one- 
 hundred pound lots, more so, for in- 
 
 PAGE FOUR 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 stance, than persons, but we like to think 
 that the particular portion of glue which 
 constitutes the silk from which we made the 
 purse was derived from the ear of a particu- 
 
 Itorch 18th, 1921. 
 
 STATE of miSOIS) 
 COCKTY of COOK j 
 
 being duly sworn deposes and Bays that he IB employed 
 
 Ey WILSON & COMPANY Inc., at Chicago. Illinois BE O^uc^~ ^^^ and 
 that he supervised the accumulation of one hundred pounds (100 Ibs.) of 
 ears taken entirely from cows. 
 
 And further deponeth and sayeth not, 
 
 before me this 17th day 
 of March - 1 9 E 1 
 
 
 - . 
 
 Notary Public 
 
 larly estimable sow called "Sukie" back on 
 the farm. To call her "Sukie" has been our 
 only flight of fancy in this entire transaction. 
 The rest was straight laboratory work. 
 Sukie's picture is on the frontispiece. And now, 
 although Sukie has passed away after the ap- 
 proved manner of porcine flesh, and has been 
 resolved into hams and bacon and sausage 
 and lard and soap, and what is generally 
 known as provisions and chemicals, Sukie's 
 ear Sukie's right ear, let us hope abides 
 with us, translated and glorified into a 
 beautiful blue purse, a challenge to tradition 
 and a contradiction of the wisdom of the ages. 
 
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 PAGE FIVE 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 While we cannot trace Sukie's history 
 back of her arrival in Chicago, we know how 
 she lost her life and her ears, and of the de- 
 velopment of her ears into glue. Now let us 
 tell what we did with the glue from the sows' 
 ears until it became a silk purse. 
 
 First, it was dispersed in water, then a 
 small amount of acetone was added to bring 
 it almost to a jelly, and a little chrome alum 
 helped to expedite its subsequent setting. 
 
 The next step was to filter it very care- 
 fully under pressure, after which it was placed 
 in the spinning apparatus. This was an en- 
 closed copper container with one (long) pipe 
 reaching nearly to the bottom and a second 
 pipe just reaching through the cover. The 
 container was immersed in warm water and 
 the short pipe connected with a pressure 
 cylinder containing carbon dioxide, i.e., 
 carbonic acid gas. The outside end of the 
 long pipe was bent over like an inverted U 
 and connected with the spinneret, which was 
 of metal, about the size and shape of a large 
 thimble, and perforated at the end with 
 sixteen very fine holes about 1/1000 of an 
 inch in diameter. The end of the spinneret 
 dipped under the surface of a coagulating 
 and hardening mixture of acetone and 
 formaldehyde contained in a large V-shaped 
 glass tube two inches in diameter with arms 
 about three feet long. The arm of the tube 
 below the spinneret was vertical, the other 
 arm extending at a slant. 
 
 Then the valve in the carbon dioxide 
 pressure tank was turned on. That forced 
 
 PAG E SIX 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 the solution in the copper container up 
 through the long tube, down through the 
 spinneret, and into the formaldehyde and 
 acetone mixture in the V tube. It came out 
 as sixteen very fine, colorless streams, so fine 
 as to be hardly visible, but these filaments on 
 the way down through the V tube joined into 
 one composite fibre which was hardened by 
 the formaldehyde. When it reached the 
 bottom it was fished up with a wire hook, 
 drawn out of the slanting arm, and from this 
 pulled over a rotating drum into a pan con- 
 taining more of the formaldehyde and 
 acetone mixture. At this point the fibre 
 was very swollen, and had hardly any 
 strength at all. It had to be removed 
 quickly and wound on a reel to dry, else it 
 would have become too brittle for any use. 
 
 After the first drying it was brittle and 
 without lustre indeed, it was a very un- 
 promising thread. But by soaking for a short 
 period in a bath of forty per cent glycerine, in 
 which it was also dyed, and after drying 
 again, the bright lustre appeared, and it 
 developed the desired soft, silky feel. It was 
 then ready for weaving, which we did on a 
 small hand loom, and the fabric was finally 
 sewed up into the form and substance of a 
 silk purse. The tassels are a continuation of 
 the warp threads, each thread being a com- 
 posite of the sixteen original filaments. 
 
 The purse is of the sort which ladies of 
 great estate carried in medieval days 
 their gold coin in one end and their silver 
 coin in the other. It is one of which both 
 Her Serene and Royal Highness the Queen 
 
 PAGE SEVEN 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 of the Burgundians in her palace, and the 
 lowly Sukie in her sty, might well have been 
 proud. When it is not on show at the Ex- 
 position, its place will be in our chemical 
 museum in Cambridge. 
 
 We admit frankly that it is not very 
 strong or very good silk, and that there is no 
 present industrial value in making it from 
 glue. The artificial silk that is made in 
 great quantity is made from cellulose, either 
 cotton or wood fibre. There is more cotton 
 and wood fibre available than there are hoofs 
 and horns and ears of animals, and conse- 
 quently of glue, and the threads are stronger. 
 
 We have no intention of producing sow's 
 ear silk for the market. We made this silk 
 purse from a sow's ear because we wanted 
 to, because it might serve as an example to 
 clients who come to us with their ambitions 
 or their troubles, and also as a contribution to 
 philosophy. 
 
 The most discouraging thing to hear, if 
 you are interested in real progress and in the 
 forward march of events, or more particu- 
 larly if you have set your heart on doing 
 something that you believe should be done, 
 is some old saw that is repeated merely be- 
 cause the words that tell it have been 
 learned, parrot-wise. 
 
 For thirty-five years we have been fight- 
 ing such expressions as "What's the use?" 
 "It isn't done," "It isn't practical," "We've 
 got no time for theories," and all the other 
 wretched substitutes for hard, earnest, 
 straight thinking. 
 
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 PAGE EIGHT 
 
On the Making of Silk Purses 
 from Sows' Ears 
 
 Things that everybody thinks he knows 
 only because he has learned the words that 
 say it, are poisons to progress. The only way 
 to get ahead is to dig in, to study, to find out, 
 to reason out theories, to test them and 
 then to hold fast to that which is good. 
 
 This making of silk purses of sows' ears 
 was merely a diversion of chemistry at play. 
 When chemistry puts on overalls and gets 
 down to business, things begin to happen 
 that are of importance to industry and to 
 commerce. New values appear. New and 
 better paths are opened to reach the goals 
 desired. 
 
 PAGE NINE 
 
PPHPI 
 
 EARNSHAW PRESS CORPORATION. BOSTON 
 
Syracuse, N. V 
 
 PAT. JAN. 21. 1908 
 
 458699 
 
 UNIVERSITY OF CALIFORNIA LIBRARY