412 SECTIONAL TRANSACTIONS.— TEXTILES. 



outstanding points of contact, from the raw wool down to the finished products of 

 manufacture, mainly in regard to practical considerations. 



It then deals with underlying theoretical considerations imposed by the amphotenc 

 characteristic of wool substance exhibited in its sorptive capacity for acids and bases, 

 especially in relation to sorption of alkali in scouring, together with the after-effects 

 of sorbed alkali, and the method devised of locating the distribution of alkali and of 

 demonstrating the origin of alkali faults. 



A discussion follows of the present knowledge of the chemical nature of wool 

 viewed simply as a natural organic product, and of its variability in composition as 

 shown by the sulphur content, and also of the relation of the latter to differences 

 in the physical structure of the fibre, and to biological considerations. 



Further, the significance is discussed of the presence of the cystine nucleus in wool 

 keratin, as applied to changes in the properties of wool on incipient hydrolysis and on 

 exposure. 



In conclusion, the promotion of pure research not directly on wool is instanced by 

 a study of the bisulphite compounds of azo-dyestuffs, demanded by the encountering 

 in practice of unexpected divergences from the accepted standards of fastness to 

 stoving (bleaching with sulphur dioxide). 



Mr. H. R. Hirst. — Use of Ultra-violet Radiation in Textile Analysis. 



Radiation from a mercury vapour lamp, after passing through a Chance's Uviol 

 screen, is filtered, leaving rays of 4046 to 3022 A units ; when allowed to fall upon a 

 number of substances, gives rise to fluorescence. This fluorescence may appear as 

 an ordinary colour or as an apparently self-luminous object. Examination of fibres 

 of wool, cotton, silk, and artificial silks give distinctive colour impressions. Oils 

 may be differentiated by their fluorescence into groups and the effect of oxidation is 

 readily seen. Saturated and unsaturated hydrocarbons show marked difference. 

 Esters of the indigoid type of dyes are fluorescent, and incomplete oxidation or 

 hydrolysis can be detected with accuracy. This can be used as check on the dyeing 

 process, so that more permanent colours can be obtained with certainty. 



The effect of sunlight and atmosphere on dyed fabrics in some cases produces 

 fluorescent compounds, whereby small amounts of fading, invisible by ordinary 

 visual observation, are made evident. 



Mr. H. Priestman and Mr. A. W. Stevenson. — Higher Drafts in Worsted 

 Spinning. 



Drafting. — In worsted spinning, the ' top,' the product of combing and associated 

 processes, is reduced to the size required for yarn formation by a series of drawing or 

 drafting processes, about ten for the finer wools. As a matter of convenience, the 

 material at each stage is wound on a bobbin and unwound for the next stage, the 

 fibres thus approaching the rollers in a reverse direction compared with the previous 

 process. Prom a convenience this reversal has come to be a trade axiom, and two 

 drafts without reversal are believed to be impossible. The authors have developed an 

 efficient spinning frame which makes two successive drafts. 



The early attempts had just enough intermittent success to be encouraging, but 

 fibres too frequently strayed and lapped on the various rollers, particularly the 

 carriers. Only when the usual mechanism was abandoned and false twist introduced 

 in the second draft did the experiments begin to be reliably successful. Merino 

 roving, usually drafted six, is drafted thirty-six with ease. Crossbred wools have been 

 dealt with in similar fashion with two false twist tubes in series, but it is quite probable 

 that a single tube will be devised. 



These experiments on successive drafting, while on the one hand foreshadowing 

 possibilities in the elimination of machines and processes, on the other throw con- 

 siderable light on what really happens in existing machinery. 



Spinning. — Spinning mechanism of the cap type has been studied from various 

 points of view. The first essential for such work was a stroboscope, and as none 

 at the time on the market was suitable, one was developed. A revolving mirror 

 produces intermittent illumination from an arc lamp beam, the instrument being 

 robust in construction and giving an image of great brilliancy and precision. 

 Peculiarities in the behaviour of the balloon such as ' cap licking ' have been explained, 

 and previously unsuspected variations in spindle speed noted and measured in the 



