Preface XXXV. 
vinegar it is found better to make alcohol, 
then, following Mr. Hudson still, we are to 
get 4 gallons of juice per bag of 200 Ib., or 
twice the quantity discussed above, viz., 
10,192,000 gallons, at 3d. per gallon, giving 
the planter 4£727,g00 a year without any 
trouble and expense to obtain; whilst it will 
probably save him both in getting rid of the 
fluid in that way instead of his present one. 
All this, I know, is on paper, but that is 
the proper place for every calculation to begin 
with; having thereby started the ball rolling 
along the right channel, I leave it to the 
readers of this book to see how far’ their 
practice agrees with Mr. Fludson’s figures and 
my theory. 
I must not forget to thank M. Leplae, of 
the Belgian Colonial Department at Brussels, 
for the loan of the blocks out of their agri- 
cultural bulletin, showing work in progress on 
cacao estates in San Thomé. These will be 
found on pp. 36, 86, 94, 96, 108, and else- 
where, and their inclusion has added con- 
siderable interest to the explanations of the 
various processes and apparatuses described 
throughout the book. 
Since I started these notes, Mr. Fawcett 
called my attention to a paragraph in the 
Pharmaceutical fournat, of London, for 
June 7, 1913 (p- 801), in which we are told 
that— 
“E, Perrot (in Comptes rend., 1913, 156, 
