118 Mr Wood, A New Chemical Test for “ Strength f etc. 
hard to filter clear, and the proteids are troublesome to remove. 
On examining the figures, it is evident that the sugar contained 
in a flour is not nearly sufficient to account for all the carbon 
dioxide evolved when fermented with yeast. Flour however is 
well known to contain a diastatic enzyme, which no doubt accounts 
for the balance of sugar required by the yeast, the figures for 
which are given in the last column of the table. The diastatic 
power of each of the flours is at present being determined with 
a view to checking these figures. 
In applying the above ideas to testing flours, there are clearly 
two ways of proceeding: (1) to make chemical determinations of 
the sugar contained in the flour as such, and of the sugar formed 
by incubating the mixture of the flour and water at such a 
temperature and for such time as is commonly used in baking 
(for instance, for three hours at 30° C.); (2) to mix the flour with 
yeast and water, and measure the carbon dioxide evolved during 
the fermentation. 
Of these two methods the latter is very much easier to carry 
out and, it is suggested, gives very valuable indications of that 
particular component of strength which is concerned with the 
volume of the loaf. If this is so, the addition of sugar to flours 
which make small loaves, should produce an increase in size, and 
this has been found to be the case by actual baking experiments : 
for instance, in one experiment the addition of one per cent, of 
sugar to ordinary household flour as bought in Cambridge was 
found to make an increase of two per cent, in the weight, and 
thirteen per cent, in the volume of the loaf. 
The author hopes shortly to make a communication dealing 
with the causes of the other components of strength. 
