MACROZAMIA SPIRALIS. 
the bulbs used for the purposes of the present investigations. The 
average yearly increase in weight of the Murwillumbah bulbs is much 
less than that of the bulbs from the two other districts. _The growth of 
the plants being so slow, it is clear that the economic use of macrozamia 
depends upon the quantity of material already available. 
From the point of view of alcohol production, the high fibre-content 
of the bulb is a disadvantage, since the solutions for fermentation must 
be considerably diluted with water in order to make it possible to work 
with them. This applies more particularly to the outer cores, the fibre- 
content of which is generally very high. The high fibre-content of the 
outer cores is shown in Table IV., which gives complete figures for 
some of the Bateman’s Bay series. 
TABLE IV.—MACROZAMIA INVESTIGATIONS. 
Particulars of Bateman’s Bay Bulbs. 
: Total , Soluble Extract 
Reference Number. Water Fibre. Starch. in addition 
ei to Starch. 
1. Outer 53-1 16°3 9-1 21°5 
4, Outer 57-2 17°8 733 17:7 
g, {Inner 62:1 | 62 12-1 19-6 
* | Outer 62°3 20°7 3°0 14:0 
ce 61°3 7:8 12°7 18°2 
* (Outer 59-1 20°9 4°8 15-2 
It would probably be possible to hydrolyze the fibre and convert it 
into fermentable sugar. If this could be done cheaply, not only would 
the yield of alcohol be increased, but the trouble caused by the presence 
of so much fibre would be removed. In this connexion it should be 
noted that wood has been used commercially as a source of alcohol, and 
that hopes are entertained of hydrolyzing peat and. making use of it. 
An experiment conducted with more concentrated acid on the fibre of 
macrozamia showed that it appears to hydrolyze readily, and a good 
yield of bodies, which reduced Fehling’s solution, was obtained, but no 
attempt was made to determine whether alcohol could be produced from 
them. Until some use can be found for the fibre, or it can be proved 
advantageous to completely hydrolyze it, attention must be confined to 
the inner core as a source of alcohol. In this connexion there is the 
possibility that the residue left after fermentation may prove of value 
as a cattle fodder. High fibre-content is a hindrance to the extraction 
‘of starch, so that it appears unlikely that the outer core has any value 
at the present time. This makes it all the more necessary to determine 
at what period of the year starch-content of the inner core reaches its 
maximum. 
In conclusion, acknowledgment is made to Mr. Gilbert Wright, 
Lecturer in Agricultural Chemistry, University, without whose interest 
and assistance the investigation could not have been carried out. 
475 
