October 21, 1920] 



NATURE 



245 



the United Kingdom, it may be said that to pro- 

 duce an additional loo million gallons of alcohol 

 we should have either to devote about 847,000 

 more acres to potatoes at the present average 

 yield of 5J tons per acre, or else to increase this 

 yield to something above 9 tons on the present 

 acreage. For the same quantity from mangolds 

 an additional 513,000 acres would be required, 

 or else a yield of 34i tons per acre instead of the 

 present average of about one-half this amount. 

 Two suggestions have been made towards the 

 possibility of effecting this increase. One is that 

 by a greater use of fertilisers and better cultiva- 

 tion the crop yield might be raised sufficiently to 

 meet the demand even with the present acreage, or 

 with a relatively small increase. As regards 

 \ potatoes, more than lo tons per acre have been 

 ' obtained in various Irish districts, so that an 

 average of 9 tons does not seem impossible. The 

 fieures given by the Fuel Research Board for the 

 mangold crop in 1919 work out to 16^ tons per 

 acre, but some years ago the average was 20 tons, 

 and 24-30 tons have been mentioned as obtain- 

 able. If the normal crop of mangolds under good 

 conditions is anything like the last estimate, no 

 very great increase in yield and acreage together 

 would be required to give the raw material for 

 100 million gallons of alcohol. 

 t The second suggestion is that, leaving apart 



P the land at present cultivated for foodstuffs, waste 

 land might be reclaimed and devoted to carbo- 

 hydrate crops for alcohol production, so that there 

 would be no diminution of present food supplies. 

 Again turning to Ireland, there are, according to 

 a recent writer, thousands, and even hundreds of 

 thousands, of acres of waste land which could, 

 without any great expenditure of money, be utilised 

 for the purpose. In this country some small- 

 scale experiments on reclamation are artu:illy in 

 progress at Holton Heath, where several acres of 

 heath land have been reclaimed and planted with 

 artichokes for a practical study of the question. 

 .'\t present, however, the work is not sufficiently 

 advanced to allow of useful deductions being 

 made. 



The general conclusion arrived at in the interim 

 report of the Fuel Research Board is that the 

 production of alcohol in any considerable quanti- 

 ties from vegetable materials grown in the I'nited 

 Kingdom is not economically possible, owing to 

 (i) insufficient acreage; (2) high cost of cultiva- 

 tion, harvesting, and manufacture ; and (3) the 

 fact that the most suitable raw materials arc also 

 important foodstuffs. The two suggestions noted 

 ;ibovc might go far to meet the first and third 

 points, but the second still remains, and it is, of 

 course, a crucial one. In tropical and sub-tropical 

 countries, where land is plentiful, labour cheap, 

 and sunshine abundant, it may be quite practic- 

 able to grow vegetable substances such as cassava, 

 arrowroot, and maize at such a cost as will make 

 them very important sources of alcohol. Maize 

 has been much used in the past, but just now its 

 price — -no doubt an abnormal one- — precludes its 

 NO. 2660, VOL. 106] 



use on a large scale. In regions such as South 

 Africa and South America, however, two or even 

 three crops can be secured yearly, and it has been 

 urged that with proper organisation and develop- 

 ment this raw material could, under conditions of 

 mass-production, become one of the most import- 

 ant supplies. 



Turning now to other possibilities, one of the 

 first to be mentioned is the utilisation of cellulose 

 materials as sources of alcohol. Two processes 

 are already well known ; others are in the experi- 

 mental stages only. The cellulose of sawdust and 

 other wood waste can be hydrolysed with acids 

 and partly converted into fermentable sugars. 

 This process has been under trial for several years 

 in America, but has not yet definitely established 

 itself as a successful manufacturing operation in 

 normal times. In countries where wood pulp is 

 made, a considerable quantity of alcohol is ob- 

 tained from w-aste sulphite liquor, a by-product 

 which contains a small percentage of fermentable 

 sugars produced during the treatment of the wood. 

 .An interesting recent proposal (Rogers and Bed- 

 ford) is one for obtaining alcohol from rice straw 

 and husk, a cheap raw material available in large 

 quantities. The straw is softened by steaming, 

 and treated with hydrochloric acid or with calcium 

 hypochlorite and chlorine to disintegrate the fibres, 

 then pulped, and the hydrolysis of the cellulose 

 and starchy matters completed by means of diluted 

 hydrochloric acid. After the conversion to sugar 

 is finished, the acid is neutralised, and the solution 

 of sugars fermented and distilled. It is under- 

 stood that arrangements have been made for large- 

 scale experimental trials of this process in India, 

 with the view of ascertaining whether the pro- 

 duction of fuel alcohol from these and similar 

 cheap cellulose materials can be definitely estab- 

 lished. 



Experiments arc also in progress to ascertain 

 whether a micro-organism can be obtained which 

 will effect the direct conversion of cellulose into 

 fermentable sugar. Success on the lines of this 

 or the preceding process would open out the pros- 

 pect of utilising a large amount of waste cellulose 

 substances as sources of alcohol. 



Among other possible new sources may be men- 

 tioned a tuberous plant, Polynuia ctlulis, growing 

 in the Andes, which is said to be now under trial 

 in France. The tubers range up to 2 lb. in weight, 

 and have a carbohydrate content comparing 

 favourably with that of mangolds. A special sugar 

 beet is also being experimented with. Little in- 

 formation, however, is available yet as to whether, 

 in the matter of yield and cost, these plants 

 offer any marked advantages over those now in 

 use. 



Our general survey indicates, therefore, that, 

 although the home production may be appreciably 

 increased, it is mainly to the organisation and 

 development of our overseas resources that we 

 must look for any very considerable increase in 

 our supplies of alcohol cheap enough to be used 

 as fuel. 



