210 THE YEAR-BOOK OF AGRICULTURE. 



Report on the Gases Evolved in Steeping Flax, and on the Composition of 



the Dressed Flax Fibre. 

 By J. his F. HODSM, M.D., F.C.S.. Prof, of Agriculture, &c. Queen's College, Belfast 

 Tin- report contains the results of investigations which were undertaken in connection 

 with the technical processes employed in the preparation of the flax-plant for textile pur- 

 poses. The attention of the author was chiefly directed to the examination of the method of 

 ping in water heated by steam, introduced by Sehenek, and usually termed the hot-water 

 BTStem. In this process, which was fully described in a report made to the British Associa- 

 tion for the Advancement of Science, at the Belfast meeting, it was found that the chemical 

 changes produced by the fermentation of the flax straw in water maintained at a temperature 

 of '.10° F., did not materially differ from those which accompany the ordinary method of 

 steeping in pools in the open air; and that, in fact. Schenck's method might be regarded as 

 merely the common process of the Irish farmer, accelerated and Subjected to BCientiflc control; 

 the peculiar fermentation by which the adhesive matters of the straw are BOftOned and dis- 

 solved being attended in both cases by the production of a considerable amount of butyric 

 acid. 



Examinations of the gaseous products of the fermentation were made at steeping-works in 

 the neighborhood of Belfast, and also in experimental works in Queen's College; the water 

 contained in the experimental vats being maintained at the requisite temperature by pipes 

 conveying steam from the boiler of an engine connected with the college heating apparatus. 

 The gasi • evolved from the fermenting liquid were analysed in accordance with the pi 

 proposed by Bun-en, and were found to consist of carbonic acid, hydrogen, and nitrogen. 

 No traces of carbonic oxide, carburetted hydrogen, nor of sulphuretted hydrogen were 

 detect.. 1. The following was the corrected composition of the mixture of gases collected in a 

 trial of Schenck's process, in the steeping-vats in Queen's College. The carbonic acid was 

 removed by the introduction of balls of caustic potash, and the residue examined by explosion 

 with oxygen, &c. 



Composition in loo vols. 



Carbonic acid 82'20 



Hydrogen 14*80 



Nitrogen :;:; 11 



Composition of dressed flax. — It was usually assumed, formerly, that by the pr 

 employed in the preparation of tlax for spinning purposes, the fibre was deprived of all the 



irhich the plant, during it- growth, had extracted from the .-oil, and that it 

 might be regarded a- po-sessing the same composition a- the cellulose of the chemist. This 

 opinion wi-. BSvera] yean ago, proved to he erroneous; and the results of the following 



analyses of samples of flax fibre -how that not merely doe- the dressed flax of commerce con- 

 tain a portion of the inorganic matters Of the plant, hut thai tin re rrmnins locked «/> in the 



We a considerable amount qf the nitrogenixed <in<l other p r oxim ate compound/ of the 



unstreped straw. The following were the method- adopted in the examination of the flax 

 fibre: — The fibre, cut into small piece-, was repeatedly treated with cold water go long as 

 any thing dissolved. The solution obtained was -trained through linen, and afterwards 



filtered, (in boiling the filtered liquid, only a slight troubling was observed; bat on the 

 addition of a tew drops of acetic acid, % precipitate of oaseine was obtained, which, after 



twelve hour- -ut.-idence, w i - collected, wa-lied, dried, and weighed In the liquid from 

 which the ca-eine v, , - Separated, when evaporated al -t to a syrupy Consistence, aloohol 



produced a bulky grayish precipitate, which w at collected, washed, and dried. The alcoholic 



liquid-. ACration, afforded a rich orange solution, and gave, on evaporation, a reddish 



rn residue, which when heated, evolved ■ strong caramel-like odor, and it- solution had 



asweeti-h taste, and afforded tin- u-ual reaction- of L r rape--ugar. The several precipitate-, 



after being weighed, were carefully Incinerated, and the weight of ask obtained In each case 



deducted. The determination- of the amount of nitrogen in the sample- were made accord- 

 ing to the method of Will, and included tir-t, t In- estimation Of tin- to' il amount Of nitrogen 

 in the dried flax, and secondly, of the amount which was retained in the form of insoluble 



