NOTES  ON  LEMON-JUICE  AND  ITS  DECOMPOSITION.  77 
gave  seven  ounces  of  juice,  having  a  specific  gravity  of  from 
1-040  to  1-046,  and  yielding  40  to  46  grains  per  ounce,  or  9*6 
per  cent,  of  citric  acid. 
The  specific  gravity  was  taken  by  one  of  Grifiin's  hydrome- 
ters, as  ordered  by  the  Board. 
1 
2 
3 
4 
5 
6 
Average. 
Crystallized  Citric  Acid 
Gum  and  Sugar 
Inorganic  Salts 
Total  grains  per  ounce 
Specific  gravities 
42-90 
3-45 
2-58 
40-05 
2-39 
1-18 
41.74 
3-03 
2-38 
39-02 
2-96 
2-22 
44.60 
3-67 
2-61 
46'  0 
3-64 
2-73 
42-53 
3-19 
2-28 
48-93 
43-62 
47-15 
44-20 
50-88 
53.27 
48-00 
1-043 
1-040 
1-042 
1-040 
1.045 
1.045 
1-044 
The  remainder  of  the  lemons  was  put  aside  till  the  end  of 
May,  and  again  examined.    The  result  was  thus : — 
1 
2 
3 
4 
5 
6 
Average. 
Crystallized  Citric  Acid 
Gum  and  Sugar 
Inorganic  Salts 
Total  grains  per  ounce 
Specific  gravities 
40-90 
4-33 
2-58 
39-65 
2-63 
1-18 
39-66 
4-51 
2-38 
36-38 
4  25 
2-22 
43-93 
3-92 
2-61 
45-77 
4-44 
2-73 
41-04 
4.01 
2-28 
47-81 
43-46 
46-55 
42.85 
50.46 
52-94 
47-33 
1  041 
1-039 
1-040 
1-038 
1  044 
1-044 
1.041 
It  will  therefore  be  observed  that,  as  the  lemons  were  kept, 
and  the  summer  advanced,  the  quantity  of  acid  decreased  (at 
first  slowly,  but  at  length  very  rapidly),  but  the  specific  gravity 
only  suffered  comparatively  slight  diminution ;  the  quantity  of 
the  juice  also  remained  the  same,  for  eight  lemons  yielded  7 
ounces  in  May  as  in  February. 
On  examining  the  remaining  fruit  in  July  the  curious  fact 
was  ascertained  that,  although  the  specific  gravity  was  1*027,  yet 
there  was  not  a  particle  of  citric  acid.  Analysis  showed  that  it 
had  all  split  up  into  glucose  and  carbonic  acid. 
Since  this,  the  nitrogenous  matter  in  the  juice  has  again  set 
the  whole  into  fermentation.  The  glucose  has  produced  alcohol, 
and  the  alcohol  acetic  acid,  thus  :  — 
Glucose.  Alcohol. 
