Polarizing Microscopic Study of the Origin and Growth of Extinction Bands in Native Cotton Fibres

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Native cotton fibres in never-dried and dehydrated states show under crossed polarized light characteristic extinction bands along their lengths. The cause of the origin and growth of these bands is still unresolved. This paper reviews critically the published literature in the light of the present author’s experimental observations On the Origin and growth of extinction bands Some plausible mechanisms for the origin of these bands from our observations with a polarizing microscope on developing cotton fibres of known ages are discussed in detail. The classical hypothesis of reversing spirals of cellulose fibrils in the secondary layers is refuted to explain the origin of the extinction bands.</span>