Experiments on Bleaching

HOME Francis

Verlag: Sands, Donaldson, Murray & Cochran, Edinburgh, 1756

Beschreibung

The recommendations arising from Home's experiments were the first step forward from the then prevalent medieval methods of bleaching towards a more science-based approach. Edelstein comments: "This book, which was perhaps the first on bleaching, paved the way for the great chemical advances which took place in the 18th century" and "Marks the overthrow of superstitions concerning the use various alkalies in the bleaching industry that had existed for hundreds of years with the help of governments and trade associations which should have known better". Bleaching methods had been static for many hundreds of years before Home's research. The basic approach was boiling the cloth in alkaline solutions (ashes), exposing it to the sun for several weeks, washing the cloth with acid and then repeating the process until a satisfactory product was achieved. It could take months. Different bleachers had different methods with only vague understandings of the chemistry involved and little sharing of experience. There was high demand for pure white cloth for luxury clothing and, following a petition from bleachers, Home, a Fellow of the Royal College of Physicians, was asked by the Board of Trustees for the Improvement in Fisheries and Manufacture in North Britain, to investigate ways of reducing processing times, improving the quality and cheapness of the final product and promulgating best practice to bleachers. The focus was on the Linen Industry, the most important producer at that time of cellulosic fabrics for clothing, before cotton fabrics became widely available. This was the first scientific study of bleaching. Home's research method was to discuss their practices with many bleachers and to carry out 136 experiments comparing different methods "before the bleachers of this country". In the preface to this work Home says; "I know no trade which is so entirely the object of chymistry as bleaching, and none that has been so little considered in that light". ''I find the most skillful bleachers understand the general theory of their art tolerably well; but being ignorant of the principles of chymistry, cannot make proper use of this theory or apply their knowledge to the advancement of their art." "But what the bleachers are most deficient in, is a knowledge of the nature and properties of those alkaline salts, or ashes, as they call them, which they make use of. Experience has taught them that these salts are to be used in different proportions; but nothing less than a chymical inquiry can disclose their hidden nature". The results of these experiments and his recommendations for improvements are described. The use of lime in bleaching was illegal at the time as it weakened the cloth. He showed that lime mixed with some types of ashes improved bleaching power without harm. He also investigated water hardness and rust marks and ways to overcome them. He recommended the use of sulphuric acid to replace sour milk to neutralise the cloth after exposure to the sun. The overall impact was to increase the bleaching power of each cycle, thus reducing the number of cycles required, lead times and costs. It was the first major revolution in the techniques of bleaching. Quarter-leather rebinding with original covers. Library stamp following the title page: ICI Dyestuffs Division, Historical Collection. Book number on rear pastedown. John Waldie's bookplate and shelf marker on front pastedown. Some glue spots on front flyleaf where a label has been removed. 1p Title, 3pp "A general Plan of the Work", then 330pp text. Browning on the edges of the first four and last four pages. Two small black marks on front cover. Otherwise Very Good. One of Edelstein's "Thirteen Key Books on Dyeing and Bleaching Before 1856". Book 0547, Ron Bibliotheca Tinctoria. Bestandsnummer des Verkäufers 000036

Bibliografische Details

Titel: Experiments on Bleaching

Verlag: Sands, Donaldson, Murray & Cochran, Edinburgh

Erscheinungsdatum: 1756

Einband: Hardcover

Zustand: Very Good

Auflage: First Edition