318 Prof. H. E. Armstrong and Dr. W. H. Glover. [Apr. 2 
y 
126 minutes; in other words, it takes about 3°8 times as long to convert 
one-half of the raffinose into melibiose and fructose as it does to change one- 
half of the cane-sugar into dextrose and fructose. 
For the following experiments the raffinose was purified by dissolving it 
in hot water, filtering the hot solution, adding a large bulk of alcohol to 
the filtrate and allowing it to stand during several days. 
given in Tables III and IV. 
The results are 
Table IV. 
Cane-sugar. Raffinose (recrystallised). 
68°4 grammes of cane-sugar (1/5 mol. 118°8 grammes of rafiinose (1/5 mol. 
ae C)oH90),) +4 c.c. of strong inver- C\gH3.015.5H,0) +4 c.c. of strong 
: tase extract in 1000 c.c. invertase extract in 1000 c.c. 
ayy. Per cent. p oe Per cent. 
ae hydrolysed. Is. ae hydrolysed. 1s 
mins 
0 9 *886 0:0 — 28 °462 0:0 — 
10 8 ‘818 lad 349 28 °156 2 °4 106 
20 7 548 16 °9 402 27 °796 Del ae 117 
30 6 °298 25 ‘9 434 27 °405 8°3 126 
40 5 ‘198 33 °8 449 26 °972 7 136 
55 — — — 26 °354 16 °6 144, 
60 2 958 50 ‘1 503 oe — — 
70 1 °895 57 °7 535 25 °743 21 °4 150 
80 0 ‘985 64 °3 560 25 °293 25 ‘0 156 
90 0 °262 69 °6 574 24-908 28 ‘0 159 
100 —0 ‘366 741 587 24°517 31 ‘1 162 
115 — = = 23 °962 35 ‘OD 165 
120 —1 °528 82 °5 631 pea a 5 
130 —1 932 85 °4 643 23 °352 40 °3 172 
140 — 2 °266 87 ‘8 653 23 ‘001 43 1 175 
150 — 2 °562 89 °9 666 22 °667 45 °7 ITZ 
160 | —2°793 91 °6 674. 22 °346 48 °2 179 
170; . pul — — — 21 -895 51°8 181 
180 —3°172 94 °4, 694 == aan ar 
190 — 3 °302 95 °3 699 21 458 55 *2 184 
200 —3 °446 96 °3 719 21 °166 57 °5 186 
220 —3 ‘524 96 ‘9 687 20 ‘662 61 °5 188 
x — 3 °950 100 ‘O — 15 “787 100 ‘0 aes 
On plotting curves representing the rates of hydrolysis in the case of the 
solution of one-tenth molecular strength, it appears that whilst 50 per cent. 
of the cane-sugar is hydrolysed in 29 minutes, 50 per cent. of the raffinose is 
hydrolysed only after 158 minutes, the ratio being 1: 5'4 as compared with 
the ratio 1: 3°8 in the experiment with the commercial raffinose. Apparently, 
the recrystallised raffinose is less quickly hydrolysed than the crude material. 
In order to see if this were really the case, comparative experiments wer 
