GENERAL MICROSCOPY 



with thallium ethylate in benzene. All these 

 methods can be used successfully for cellu- 

 lose fibers and polyvinyl alcohol. 



Fiber Microscopy and Morphology 



Fibers can be classified as: (1) protein 

 fibers, (2) cellulose fibers, (3) synthetic fibers. 



Protein Fibers. The most important pro- 

 tein fibers are the keratin fibers. As regards 

 textile techniques wool is the chief one of 

 these. In addition to wool, are hairs that are 

 used for "effect" or for other special pur- 

 poses, e.g., mohair, cashmere and goat hair, 

 from the Angora goat, the Cashmere goat 

 and the common goat, respectively, camel 

 hair, llama, alpaca and Vicuna, allied to the 

 camel. There are many kinds of fur-produc- 

 ing animals, for instance : the rabbit, musk- 

 rat, skunk, mink, wolf, ocelot, seal, tiger cat, 

 lamb. Brush fibers come from the horse, 

 cow, pig, marten, skunk and squirrel. 



It is important to be able to identify all 

 these fibers microscopically. No good sys- 

 tematic method for this exists as yet. An im- 

 portant contribution has been made by Wild- 

 man who systematically classified the scales, 

 according to the shape of the margin, as fol- 

 lows : 



1. (a) Smooth: Margins which are on the 



whole smooth with little or no inden- 

 tation. 



(b) Crenate: This means "notched" and 

 is restricted here to margins which 

 have fairly shallow indentation and 

 in which the majority of the "teeth" 

 taper to a relatively sharp point. 



(c) Rippled: Margins having indentation, 

 the majority of which are deeper than 

 those of the crenate type and in which 

 most of the "peaks" are rounded in- 

 stead of ending in sharp points. 



(d) Scalloped: Scalloped margins are rela- 

 tively rare among the textile fibers. 



2. The distance apart of the external margins 



of the scale comparison is at a stand- 

 ard magnification, 

 (a) Close: Successive scale margins along 



the fiber which are very close together 

 l:h (length: height) = >10. 



(b) Distant: Scale margins which are far 

 apart in the direction of the long axis 

 of the fiber l:h = 3:10. 



(c) Near: Successive scale margins which 

 are spaced at distances intermediate 

 between the above extremes l:h < 3. 



3. Type of Over-all Pattern. All the following 

 patterns may be qualified by the 

 terms defined above to indicate the 

 form of the scale margins and their 

 spacing intermediate patterns can be 

 described by combining the names of 

 the basic patterns. 



(a) Mosaic: The term is self-explanatory 

 but is qualified as follows: 

 Regular mosaic: The units of which are 

 very approximately the same size. 

 Irregular mosaic: The units of which 

 are obviously not of the same size. 



(b) Waved: Some form of wave occurs 

 commonly in scale pattern and the 

 term is applied to any pattern which 

 appears to be wavy; where the waves 

 follow a continuous course around the 

 fiber their uninterrupted character is 

 inferred from the term waved without 

 further qualification. 



Interrupted wave. A pattern which 

 has a general wave form but which is 

 clearly interrupted falls into this 

 category. 



Simple regular wave: This type has 

 waves which are continuous and are 

 of approximately the same wave- 

 length and amplitude. 

 Streaked wave: The waves are inter- 

 rupted at regular intervals by longi- 

 tudinally running bands of steeply 

 inclined scale margins. 

 Shallow, deep and medium waves: 

 These adjectives indicate the rela- 

 tive depth of the majority of the 

 waves in the pattern irrespective of 

 the distance apart of the scale mar- 

 gins. 



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