xvm. 



The Commission submits that this matter should be investigated more 

 fully, especially as regards its use for other purposes than the manufacture of 

 paper proper, and, therefore, recommends that Messrs. R. W. Sindall and W. 

 Bacon, the well-known paper technologists in London, be asked to report on 

 the potentialities of the fibre of our prevalent prickly-pears. If such report be 

 found satisfactory, having in mind that the fibre is from our point of view a 

 by-product, then the estabUshment of pulp manufactories in the dense prickly- 

 pear areas might be considered. 



P. Utilisation of the Mucilage. 



Some samples of mucilage from the Queensland pest pear were submitted 

 to the Imperial Institute for examination, but as they had undergone some 

 fermentation it was not proceeded with in detail. 



An American investigator, who has given attention to the mucilage 

 occurring in the stem of one of the New Mexican Opuntias, found that in a dry 

 condition it contained galactan (15 per cent.) and a pentosan (31 per cent.), as 

 well as 12 per cent, of ash, whereas the ripe fruits had only a trace of galactan, 

 and 1-57 per cent, of pentosan, but a large quantity of fructose and glucose. 

 A 10 per cent, "solution" was found to be very viscous, but had poor adhesive 

 qualities, and did not prove satisfactory as a paper glaze. It is suggested by the 

 Imperial Institute that the mucilage might serve as a glaze for cheap cotton 

 stuffs. 



It has been used in Northern India as an addition to whitewash, while 

 in Southern India it is employed in the making of a kind of plaster, which is 

 largely used in the internal decoration of edifices, and is said to have a fine 

 texture and to be capable of receiving a fine polish. 



Other methods of employing this body, which is so conspicuous a feature 

 in the composition of prickly-pear, might be suggested. However, the question 

 of determining the commercial value of the mucilage is one for a chemical 

 technologist. 



G. As a Source of Oxalic Acid. 

 All parts of the prickly-pear, as has been indicated by one of us, 

 including even the root system, contain in relatively large amount oxalate 

 of lime in a crystalised condition, as well as other salts of oxalic acid in a 

 dissolved state. There are grounds for concluding that the former could be 

 readily isolated by mechanical means only. As is well known, oxalate of lime 

 is the principal source for the manufacture of oxalic acid that finds so large a 

 place in the industrial arts. In practice this salt is decomposed with sulphuric 

 acid, yielding under the process sulphate of lime and oxalic acid— bodies that 

 are readily separable. At present ordinary sawdust is employed as a source for 

 the body referred to, but contains oxalate of lime in far less amount than do 

 prickly-pear plants. 



H. Utilisation of the Colouring Matter in the Fruit 

 The fruit of many prickly-pears, including most of those naturalised- in 

 Australia, contains a magenta colouring matter. That obtained from 0. dillenii 

 is used in Sicily as a dye for basketware, while in the Andean region, and in Mexico 

 and adjacent parts of the United States, the coloured juice of local species is 

 used to colour various beverages and foodstuffs. 



The dye obtained from a New Mexican species of Opuntia has been 

 mvestigated by an American chemist. The mucilaginous matter was first pre- 



