Title: |
Silk: A World History |
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Author: |
Aarathi Prasad |
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Category: |
Non-fiction |
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Rating: |
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Date Reviewed: |
January 24, 2025 |
Silkworms were first domesticated by Neolithic Chinese farmers thousands of years ago (they are the first domesticated insect). The farmed silkworms now grow cocoons that contain three times as many fibers as the cocoons spun by wild moths. The domesticated cocoons are so thick that the worms cannot escape on their own, they require human intervention to free them so that they can reproduce. Of course, most of the silkworms are destined to be boiled and dried without ever leaving their cocoons. They are sun dried, and then the fibers unwound, spun into threads, and woven into marvelous silk fabrics. I did not realize how far silkworms had spread, and how long ago in history. It wasn't just the orient that grew silkworms. Renaissance Europe had groves of mulberry trees full of silkworms in France and Italy. The Dutch had a colony in South America called Surinam. Although the primary wealth from this outpost was from sugar plantations, huge New World moths were discovered that yield intriguing silk threads. The description of the cruelty and barbarity of the ruthless Dutch colonizers in Surinam is eye opening. The brutal Dutch slavers thought to deter escape by severely punishing anyone who was caught fleeing slavery - the Dutch roasted people alive, decapitated them, had them drawn and quartered, and old men broken on the rack - any cruel torture, and apparently the Dutch used it. I had never even heard of this awful colony before. My favorite discovery in this book is that the "eye dots" on moths wings are carefully evolved structures. The eye dots have scales that vibrate at certain frequencies, absorbing soundwaves at particular wavelengths. Also, the moths are covered in tiny, fine hairs that absorb and convert sound waves into heat energy. These moth structures dampened energy at the frequency ranges used by bats trying to echo-locate their prey. Many moths fly at night, which is when bats hunt. These evolutionary innovations help moths disappear from the soundscape that bats construct with their vocalizations. In addition to the many different species of cocoon-spinning moths, there are mollusks that live in the Mediterranean Sea that extrude long fibers into the rocky floor to anchor themselves upright at the bottom of the sea. Humans harvesting these mollusks found that those anchoring threads could be woven into a wonderful silken material. Unfortunately, it took many mollusks to yield enough fibers to make even small garments like gloves and socks. Now the mollusks are near extinction, suffering for virus spreading through the warming waters of the Mediterranean, and stressed by pollution and other human activities. Spiders also produce high quality silk fibers. There have been a number of attempts to utilized spider silks, but so far it has proven impossible to scale up to industrial levels of production. Spider silk is strong and resilient, and contains proteins that aid in healing. Bandages woven from spider silk give a boost to healing wounds. The strength of silk fabrics was noticed long ago. The Mongols wore silk shirts under their lightweight armor. Although arrow shafts could punch deep into the body, the silk itself did not get split, and sometimes it was possible to extract the arrowhead simply by pulling the unbroken silk fabric out of the wound. Later, the toughness of silk was noticed with respect to bullet wounds - sometimes the bullet could be extracted by pulling the silk garment out of the bullet hole. This lead to the invention of bullet proof vests. The inventor of the first bullet proof vests offered one to the White House, but the press secretary turned down the offer. A short time later, President died from a gunshot fired by an assassin. Had he worn the vest, he would have survived the attack. The tough silk fibers are also woven into parachutes. The end of the book describes the potential uses of silk, if only scientists could perfect the creation of silk to match what the silkworms and spiders can make. Our world is
littered with microplastics. Silks could be used instead for many of the products that currently employ plastics. But silks are organic, and will degrade into harmless components that do not harm the
environment.
Overall, this book tells the reader just about everything you might wish to know about silk. The author has done an amazing amount of research, seemingly uncovering many forgotten
scientists and entrepreneurs who have attempted to make silks profitable. |
