I just finished Aarathi Prasad’s new book, Silk. The author, a molecular geneticist, and bioarcheologist raised in the Caribbean, wore silk saris all her youth. Her book explains silk’s origins, history, surprising varieties, and contemporary uses.
Of the many things I learned about silk, some highlights include:
Bombyx mori, the silkworm, was likely domesticated in China after arriving from Merv, the great city of present-day Turkmenistan, along the former course of the river some 7,000 years ago. Prasad unearths evidence that one of the earliest city builders, the Indus Valley Civilization (7,000 BCE to 3,500 BCE), wove silken garments.
While the worm and moth can no longer survive in the wild, the genetic variations of the worm, which have spread around the world, now number in the thousands.
The book’s first section is devoted to the extensive history of silk production, domestication, and geographic spread. Early history is filled with an unusual cast of fascinating, obsessive characters, each contributing to the silk we wear today.
Section 2 is devoted to an even more compelling arcana. The first five chapters are dedicated to the golden silk of the mollusk Pina nobilis, a meter-long native to the Mediterranean and other coastal habitats. Pina nobilis anchors itself to the sandy sea floor via fibers that are more than a foot long. These fibers are woven into a rare form of silk, often reserved for royalty and elites. Some garments were even valued at several kilograms of gold!
Prasad’s history of this fabulous material, from the time of the Pharaohs to World War II and contemporary studies, is one of the book’s most fascinating stories.
Then come the spiders! We all know that spider silk is remarkable, but how remarkable is a surprise, at least to me. Spiders produce many types of silk, each adapted for a particular purpose, such as anchoring webs, egg cases, trapping fibers, and prey immobilization. Some of the fibers are far smaller than those of the silkworm and much stronger.
Most attempts to mass-produce spider silk over the centuries have failed. One semi-successful venture during World War II was using spider silk for the crosshairs in bomb sites due to the fiber’s minimal size and optical properties.
The story of Silk is not over. Part 3 describes a potpourri of modern attempts to produce silk via biotechnology: the genetic reengineering of cows and ewes to produce silk proteins in milk, the creation of hybrid worms that produce mixtures of Bombex and spider silk with favorable properties, and even more adventuresome forays.
I recommend the book to all who enjoy the look and feel of the remarkable fabric and a good tale that mixes science, industry, and historical sleuthing!
