MUSEOS DE LA SEDA / SILK MUSEUMS

centre of research and innovation in the town of La Alberca (Murcia). This institution, the Estación Sericícola de Murcia (Sericultural Station of Murcia, SSM), established in 1892 and active until 1976, was the first and the only one in Spain with this assignment. Its activity left a rich patrimony of ancient tools related to sericulture and it is still active on silkworm research through its administrative continuity, the IMIDA. Below, this pro- cess will be explained more deeply. 2) Antecedents The silk consists of a proteinaceous secretion produced by some groups of arthropods with very diverse biological functions. In this sense, the silk is a whole family of materials that at the molecular level show small differences on a common universal design. This design consists in the repetition of the amino acids Glycine and Alanine, which adopt a hard and crystalline secondary structure known as beta-sheet. These domains are separat- ed by other domains constituted by amino acids that produce an amorphous and flexible secondary structure. This configuration explains the unique combination of strength and elasticity of silks. There are at least 28 groups of arthropods that produce silks, for a vari- ety of functions. For instance, spiders segregate a complex set of silks that constitute a web for predatory purposes. Some mites produce a very thin silk where they are protected dur- ing its life cycle. Other insects such as honeybees or crickets segregate silk for the protec- tion of larvae. But, in spite of the diversity of functions and origins, the word silk usually describes the silk produced by the Lepidopteran insect Bombyx mori L. This insect makes a cocoon in order to protect the pupae during the process of metamorphosis. This cocoon is made by means of the spinning of a single filament, of up to 1500 meters in length, composed of a fibrous protein, named fibroin, coated by a globular and sticky protein, the sericin. The filament that constitutes the cocoon, after the sericin removal using hot water, can be processed to be used as a textile fibre. This process was discovered in China in the Neolithic, where the oldest remains are dated around 8500 years ago, and it was the origin of an industry of great economic value that is still important nowadays. The production of raw silk cocoons worldwide is about 750,000 Tm by year with an economic value estimated in tens of billions of dollars. The main producer is China (75%) followed by India, Uzbekistan and Brazil. During millennia, silkworm rearing and silk production were exclusively performed in China. The silk fabrics produced were distributed to the Ancient World through the Silk Road, a variety of routes connecting China and the Western World, constituting one of the most fascinating items of human civilization. The demand in the West was very high, and the origin and nature of the product unknown. But around the sixth century, the secret of the fabrication of silk arrived in Europe through the Byzantine Empire. The production of silk and the manufacture of textiles was a very important industry in Europe for several centuries. It was extended throughout many regions, being predomi- nant in certain areas such as North of Italy, Centre and South of France and Mediterra- nean Coast of Spain. It constituted the basis of the splendour and development of cities such as Lyon and Valencia. The silk industry in Spain had a great importance, being its apogee from the mid-fifteenth century to the late eighteenth century. In this period, this 57