54 



as an average yield per acre, 80 gallons of alcohol 

 may be obtained per acre. The cake, consist- 

 ing of the refuse after pressing, could be used 

 as a stock food. When one considers that this 

 matter of so utilising 0. ficus-inddca has been in- 

 quired into in Italy, where the fruit has a com- 

 mercial value as an article of food, and is there- 

 fore not a waste product, it seems that research, 

 from the same standpoint, into the potentialities 

 of the fruits of Queensland prickly-pears, which 

 are certainly waste products from our point of 

 view, should merit some attention, particularly 

 as our pest pears, especially the " Gayndah 

 pear," are so prolific in their fruit production. 



"Whilst in England the advice and assistance 

 of Professor "W. R. Dunstan, Director of the Im- 

 perial Institute, London, were sought in regard 

 to the question of the utilisation of Opuntias or 

 of their constituents in the industries. He in- 

 formed the Commission that the matter'had been 

 brought before the institute on various occasions 

 previously by the Governments of Australia, 

 South Africa, and St. Helena. Neither he 

 nor Dr. T. Henry, the Superintendent of the 

 Laboratories, was favourably impressed with the 

 commercial possibilities. Their investigations led 

 them to believe that Opuntia fibre could not com- 

 pete with other cheap fibre plants which were 

 more suitable for paper-pulp making; nor could 

 the plant compete with other substances as a 

 possible alcohol producer. The possibility of 

 making use of the mucilage had not been taken 

 up by the institute. 



Professor Dunstan kindly furnished the 

 Commission with a report dated 27th June, 1913, 

 the following part dealing with the question of 

 alcohol production: — 



" In 1908, the remarkable aimouncement 

 was widely published that a chemist in Brisbane 

 had discovered valuable commercial possibilities 

 for the prickly-pear, which led him to conclude 

 that, instead of the plant being ruthlessly de- 

 stroyed, its cultivation ought to be encouraged. 

 The principal claims put forward were — (1) 

 That from one ton of prickly-pear seven gallons 

 of alcohol could be prepared at a cost not exceed- 

 ing 3s. 6d. per gallon, whilst the refuse could be 

 made into a nutritious cattle-food; (2) that the 

 plant yields an excellent sugar, two tons of 

 prickly -pear yielding as much sugar as three tons 

 of sugar-cane, and of equal quality; and (3) that 

 the fibrous nature of the material renders it suit- 

 able for the manufacture of paper, strawboard, 

 and other articles, and that these could be more 

 cheaply produced from prickly-pear than from 

 any product now used for the purpose. 



' ' The suggestion with regard to utilising the 

 plant for the manufacture of alcohol is not new. 

 Proposals of this kind have been made previously 

 in New South Wales, Mexico, Spain, India, and 

 other countries, but it does not appear that alco- 

 hol has ever been obtained from this source on 

 a commercial scale. The juice of the fruit con- 

 tains saccharine matter, and undergoes spon- 

 taneous fermentation; the alcoholic liquid thus 

 obtained is iised by the natives of Mexico and 

 other countries as a beverage. It seems impro- 

 bable, however, that this liquid could be profit- 

 ably employed as a source of alcohol, for the 

 following reasons : — 



' ' Alcohol of 90 per cent, strength can be 

 manufactured from cheap materials, such as 

 maize and potatoes, at a cost of from 6d. to Is. 



per gallon, depending on the market price of the 

 raw materials and other local factors. It is evi- 

 dent, therefore, that the production of spirit 

 from prickly-pear juice could only be remunera- 

 tive in a country which had no other crops avail- 

 able for the purpose, and which had a heavy duty 

 on imported alcohol. Moreover, the researches 

 of Ulpiani and Sarcoli in 1902 have shown that 

 not only would the manufacture of alcohol from 

 prickly-pear juice be unprofitable, but also that 

 is it scarcely practicable. These chemists found 

 that the juice of the fruit of the prickly-pear 

 contains 12-8 per cent, of sugar, which consists 

 not of sucrose (or cane-sugar), but of a mixture 

 of glucose and fructose. The spontaneous fer- 

 mentation of the juice is due to the action of a 

 natural yeast which occurs on the fruit, and has 

 been termed Saccaromyces opuntim. This yeast 

 does not ferment cane-sugar, but only glucose 

 and fructose. The fermentation takes place very 

 slowly, and even after a long time the proportion 

 of alcohol is not equivalent to the amount of 

 sugars originally present. Added yeast, however, 

 is rapidly suppressed by 8. opuntim, and it would 

 therefore be necessary to kill the latter by steri- 

 lising the juice before introducing the ordinary 

 yeast. On account of the expense of sterilisation, 

 it is regarded as desirable to find a yeast capable 

 of producing alcohol rapidly in the presence of 

 the natural yeast (S. opuntia,), as only in this 

 way could the manufacture of alcohol from the 

 juice become practicable. 



" With regard to the manufacture of sugar 

 from the prickly-pear, it is obvious that, if the 

 contention of Ulpiani and Sarcoli that the juice 

 contains only glucose and fructose is correct, no 

 cane-sugar could possibly be obtainable. ..." 



However, the opinion embodied in this re- 

 port, notwithstanding experimental data, would 

 seem to point to an opposite conclusion. 



Utilisation op the Fibre for Making Paper 

 Pulp, Boards, &c.' 



Don P. Gonzales, of Jerez (Spain) mentioned 

 that the thick trunks of the common species of 

 Opuntia, 0. ficus-indica and 0. amydcea, had 

 been tried as possible materials for paper-mak- 

 ing, but had not proved a success. Further 

 particulars were wanting. 



Whilst in Italy, one member of the Commis- 

 sion devoted considerable attention to the pos- 

 sibility of utilising prickly-pear fibre in this way, 

 visiting the chief centres for the manufacture of 

 paper pulp. A journey was made to Milan, the 

 most important Italian centre of the paper 

 manufacturing industry, where visits were paid 

 to the Milan house of Ambrozio Binda and Co. 

 Sig. A. Binda stated that the technical manager, 

 Sig. L. B. Donzelli, thoughf that it would not be 

 practicable to use the woody fibre of the local 

 prickly-pear for paper pulp, owing to the great 

 deal of refining that would be necessary for it 

 to undergo, and that even for making " boards " 

 it would not be likely to compete with the 

 cheap material already in use there. Interviews 

 were also held with the city representatives of 

 the following companies or paper mills: — Car- 

 mignano Mill, Brenta-Padova ; J. Sesana and Co., 

 Crusinallo ; Bagatella and Co., Milan ; The Rossi 

 Cartiera, Milan; Sig. E. Pirola, of Pirola and 

 Co. 



