306 INTERNATIONAL CONGRESS OF VITICULTURE 



The treatment of such material at the paper mill for its conversion into 

 pulp would not differ practically from that followed in the working of 

 esparto. 



The stems, before being digested with caustic soda, could be boiled for 

 some time in the digester, in order to recover the cream of tartar, which they 

 contain, and which, upon cooling and standing of the liquor, would crystallize 

 out in the usual way, as in the case of the working of pomace for the same 

 purpose. The mother-liquor, if fuel is to be had cheaply, after it has depos- 

 ited the cream of tartar, could be condensed for the preparation of tannic 

 extract. 



Supposing the stems have been packed in a dry condition, they would 

 contain, according to Girard and Lindet's analysis, made on dry stems of the 

 Aramon grape, 3.37 per cent of cream of tartar and 10.23 per cent of tannin; 

 but a more conservative estimate based on Ottavi-Marescalchi's figures, 

 would be from about 1 to about 2 per cent of cream of tartar, and from about 

 1,5 to about 3 per cent of tannin. 



Of course, only part of these by-products could be recovered, but, I be- 

 lieve, in sufficient quantity to pay for their extraction. 



The stems would then have to be boiled with caustic soda of convenient 

 strength, under convenient pressure, for a sufficient time, to remove the non- 

 fibrous constituents, leaving the cellulose in a more or less pure form, 

 according to treatment. 



The washing of the fiber in the hollander and the bleaching would next 

 be accomplished in the same manner as in the case of esparto or straw. 



Where sulphur can be obtained cheaply, as, for instance, in Sicily, the 

 bi-sulphite process could probably replace conveniently the soda process in 

 the preparation of the pulp, and likewise where electro-energy is within easy 

 reach, such as in the north of Italy, the Kellner process, by which the ma- 

 terial is digested in a solution of sodium chloride at 126 C. under the action 

 of an electric current. 



The advantages of the suggested utilization lie mainly in the following 

 facts : 



First The low cost of the raw material, which is at present practically 

 not utilized. 



Second The fact that wineries are already provided with machinery 

 suitable for its packing, thus reducing considerably the cost of its removal. 



Third The fairly abundant supply of said material in important wine 

 producing countries, such as Italy, France, etc., and within a comparatively 

 short radius. 



Fourth The possibility of extracting from the stems, without departing 

 from the industrial process necessary for their transformation into pulp, the 

 valuable by-products above stated, viz: cream of tartar and tannic acid. 



Take, for instance, the case of a wine plant working, say, 300 tons of 

 grapes daily for thirty days. There would be a production of 360 tons of 

 stems, which, at nominal net price of $2.50 per ton (a dollar more than its 

 value in manure, and almost more than three times its value as represented 

 by the price paid for grapes), would add something like $900 to the revenue 

 of the wine maker. Freight expenses would have to be added to this cost 

 of origin. 



