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Dr. W. L. Balls. The Existence of Daily 



but this difference is less obvious when both are mature ; the convolutions, 

 which are characteristic of the lint, are not so well shown by the fuzz, on 

 account of its thicker cell wall, but they are present, and, in sum, we may 

 reasonably anticipate that any phenomenon shown by the fuzz may be 

 expected to be found, in some modified form, amongst the lint-hairs as well. 



Experimental Metliods. 



The first observation of these growth-rings was accidental, a laminated 

 hair being noticed by the writer in some cotton treated by Cross and Bevan's 

 method for the preparation of cellulose xanthate, with subsequent hydration.* 

 The hair in question might well have originated from some source other than 

 the cotton plant, but subsequent results have shown that it was a fuzz-hair. 

 In any case, the phenomenon was so striking, and might prove to be so 

 intimately related to the writer's previous researches in Egypt, that a 

 systematic examination was undertaken, with the assistance of Dr. Mary 

 Cunningham on the chemical side. 



It was clear that the hydration process, or jelly formation, would need to 

 be carried far enough to swell the wall of the cell to quite five times its 

 initial thickness (fig. 1), and yet would have to be arrested some long way 

 short of complete dissolution. In effecting this control we were able to take 

 advantage of recent work by Cross and Bevan on the effects of CS2 in 

 conjunction with 9 per cent. NaOH (Engl. pat. 8342/18). At the best, 

 however, we were unable to bring the process to complete certainty of 

 demonstration in any one sample, so far as the growth-rings in the lint 

 were concerned, though invariably successful with the fuzz. It seems 

 evident that the attainment of the precise step at which the former are 

 sufficiently swollen, and yet not too much, must be a matter of such careful 

 chemical adjustment that the individuality of each hair may be concerned, 

 and hence it must remain a matter of chance to a notable extent.f (Eigs. 1, 

 6, and 7.) The point needs emphasis, for the sake of other workers. 



* Cross and Bevan, ' Eesearches on Cellulose,' 1905-18 (Pat. 8700/92, etc.). 



f \_Note added in Press, April 28, 1919. — After various trials Dr. Cunningham has 

 obtained preparations with cuprammonium (Schweizer's reagent) which show these rings 

 as clearly as any made with CSj and NaOH, for occasional hairs only. It is of further 

 interest that some of these preparations were made from cotton cellulose, deprived of 

 cuticle, e.g., fully bleached and subsequently boiled in solution of alkaline sodium sulphite. 

 By comparing various hairs in these preparations it seems clear that cuprammonium 

 usually contorts the growth-ring strata too much. Thus, fig. 63, in Mr. Matthews' book 

 on ' Textile Fibres,' undoubtedly represents growth-rings thus deformed, as usual, beyond 

 obvious recognition as such. I am indebted to Dr. Coward for bringing to my notice 

 another example, though a more dubious one, of unconscious observation of these 

 structures. W. Minajeff (' Ueber das erhohte Anfarben de rmercerisierten Baumwolle 

 und dessen Ursachen," in ' Zeitschrift fiir Farben-Industrie,' vol. 15, p. 234 (1907), 



