THE HOT- WATER PROCESS. 299 



importance to its chemical powers, both as regards its 

 action on the nitrogenized extractive matter of the straw 

 and the quality of the fibre produced. In the first pro- 

 cess the solvent power was clearly not due to the steam, 

 but to the heated water resulting from its condensation, 

 and as this was always in contact with fresh steam, it was 

 necessarily kept up to its maximum temperature of 212. 

 Now it is well known to chemists that albuminous solu- 

 tions containing even a very small proportion of albumen 

 (1 in 1000 parts for instance), coagulate at a temperature 

 of 180, and then become insoluble in water; and it is 

 always considered that flax fibre is more or less injured if 

 submitted to a temperature beyond certain fixed limits. 

 These two important points were duly regarded and taken 

 advantage of in Buchanan's process. The temperature of 

 the steep was kept between 150 and 180, and the opera- 

 tion, both as regards time and produce, more satisfactorily 

 performed. The mechanical arrangements, too, were well 

 worth attention; they were equally simple and inexpen- 

 sive, besides which they were completely automatic, thus 

 saving the labour and risks consequent upon carelessness. 

 An entirely new principle of action was introduced, by 

 which a great saving of time was effected three to four 

 hours now being quite sufficient for the operation. In- 

 stead of the straw remaining all the time in contact with 

 the liquid which becomes speedily charged with the ex- 

 tracted matter, and thus deprived more or less of its solvent 

 power, this latter was, by a very simple but effective con- 

 trivance, frequently withdrawn from the steeping vat, and 

 again forced into it at a regulated temperature, by which 

 it was each time brought into contact with fresh surfaces, 

 and more efficiently extracted the soluble matters of the 

 straw. A familiar instance of the effect produced by 

 exposing fresh surfaces to the action of a solvent, is 

 readily seen in the immersion of a lump of sugar in 



