462 Proceedings of the Royal Irish Academy. 



Edimatimi of loss of weight on drying. 



7-6805 grms. flax fitre after drying at 100° C. for 12 tours ^^eighed 

 6-796 grms., loss of weight 0-8845 grms. = 11-5 per cent. 5-07625 

 grms. of yarn manufactured from the same flax, after drying 12 hours 

 at 100° C, weighed 4-5800 ; loss of weight 0-49625 grms. = 9-7 per cent. 

 After the retting of the flax, the gummy matters which were 

 originally, says Kolb, uniformly spread over the fibre, disappear, and 

 are replaced by numerous briUiant scales of a resinous appearance, 

 equally distributed in the substance of the fibre, and in a manner 

 adhering by their roughness to the filaments. 

 These scales have a light amber hue, and are 

 deepened in colour by alkalies, in which they 

 can be entirely dissolved. By the mechani- 

 cal process of hackling, large quantities of 

 scaly matters are removed from the fibre. 

 This substance, the nature of which is so 

 little known, has been very differently named 

 by many chemists; Berthollet calls it yellow 

 colouring matter ; Kirwan considered it a 

 resin, differing from the true resins by its 

 insolubility in the essential oils; M. Eouget 

 de Lisle thought that it was, in combination 

 with two others, of the nature of gummy 

 extractive matter ; G-rimshaw ascribed the 

 colour of raw flax and cotton to the pre- 

 sence of iron. In pursuance of the course 

 of investigation here undertaken, it was con- 

 sidered proper to begin by studying the cha- 

 racter of the bodies extracted from the flax 

 by ether and alcohol, which was done in the 

 following manner : — In order to obtain a 

 sufficient amount of the bodies soluble in 

 ether, the extraction was effected on a large 

 scale in an apparatus which will be seen, by 

 the accompanying sketch, to consist of a 

 4-litre bottle, with a tubule at the bottom, 

 fused in an inclined position for better run- 

 ning off, which held about 400 grms. flax 

 each time. The tube B carries the ether 

 vapour from the flask underneath into the 

 extraction bottle, and thence into a cooler, 

 where it is condensed. The tube C carries the ether charged with 

 wax and colouring matters back into the flask. Though all the most 

 approved plans proposed for ether and alcohol extraction were tried, 

 none were found so effective as the one here described, which during 

 three days extracted 1-5 kg. flax with 4 litres of ether. The ethe- 

 real^ solution gradually turned light-green, and finally rather dark. 

 On the cooling of the concentrated solution, a substance separated 

 in white mammillary or flocculent masses. The hot extract was 



