FIBERS (TEXTILE) 



just brought to the boil, this if necessary be- (keratin) which is Hmitcd in quantity as 

 ing repeated, scale layer and cortex disin- compared with celhilose, microorganisms 

 tegrate. The cement substance between the capable of attacking this complex substance 

 medullary cells also disintegrates. are not found as commonly as cellulose de- 

 Bilateral structure of wool. The Japanese, composing organisms. Nevertheless, the 

 Horio and Kondo, found that if frizzy hair keratin-attacking organisms are sufficiently 

 was stained with Janus green or Ponceau R represented to necessitate adequate precau- 

 the hairs showed a bilateral structure, one tions in handling and storing woolen prod- 

 lengthwise half showing greater affinity for ucts. 



Ponceau R and the other a greater affinity Wool can be easily attacked by bacteria 

 for Janus green. They concluded that it had and by molds. The most severe is caused by 

 a bilateral structure. Mercer has called the several strains of Penicillia and/or Asper- 

 two halves the para-cortex and the ortho- gillus, which cause colored spots. These 

 cortex. spots, which are serious because they are 

 The difference between the two parts of difficult to remove and may moreover cause 

 the fiber is very easy to see if the wool hair trouble in dyeing, are a fairly superficial at- 

 is first stained with methylene blue and if tack usually caused through microorganisms 

 this is followed by Allworden's reaction. The growing on fiber such as wax, soap, oil, fat or 

 inside curve of frizzy hair is then much nitrogenous waste products, 

 more strongly affected than the outer. Molds of the genera Alternaria, Stem- 

 Examination of cross-sections shows that phylium, Oospora and Penicillia cause the 

 on the whole the ortho-cortex consists of spots on wool but to a certain extent attack 

 larger cells. the wool as well. Other strains causing such 

 The difference between para and ortho- effects are Aspergillus, Fusarine, Tricho- 

 cortex is found to some extent with all kera- derma and Cephalothecium. 

 tin fibers. Although mohair was originally The aerobic bacilli include several which 

 described as 100 % ortho fiber, close examina- may attack wool. One of the best known is 

 tion has shown that a part of this is also para Bacillus mesentericus. Furthermore, there is 

 cortex, although the percentage is low. Bacillus subtiHs. A very strong attack is 

 The dividing fine between the para and caused by Actinomycetes which quickly 

 ortho parts is usually very irregular. In some brings about a loss of mechanical character- 

 cases there may be two ortho parts with the ig^jcg Qf ^^e wool. There are strong indica- 

 para cortex between, while fibers have also ^-^^^^ ^j^^^ ^j^ig damage is caused only if the 

 been observed with a central ''ortho" strand ^^^^ ^^^ already been damaged mechanically 

 enveloped in para cortex. ^^ chemically. 



Fluorescent microscope exammation shows proteolytic bacteria and molds rapidly 



that besides the differences between the cor- ^^^^^^ ^^^^^ ^^^^ ^^^^^ favorable conditions, 



tex parts there are also fairly strong differ- ^^^^^^^ ^^^ ^.^^^^^^ ^^^ intercortical 



ences between the scales 01 the outer and in- , , ,. • , ,• • . ^i • ji 



, , J., T xi, r J J cement, and disintegration into the spindle- 



ner curves of wool fiber. In the case ot dyed , ' „ "= ^, ^ ^ 



fibers, the scales on the ortho are found to shaped cortex cells occurs. These effects can 



allow dye to penetrate better than those on be seen directly with microscopic examina- 



the oara side ^^°^" '^^^^ ^^^^ should be distinguished from 



normal mechanical damage because hyphae 



Microbiological and Biological Attack a^^ci sometimes spore carriers are usually 



on Wool present. 



Microbiological Attack. As wool and Especially after staining with 0.1 % meth- 



other animal hair contains a specific protein ylene blue, the hyphae are easy to see, while 



353 



