596 Dr. EK. f. Armstrong. [July 29, 
and that such may be the case is by no means improbable, as it is conceivable 
that if glucose were formed against a maltase template,* it would be present 
initially only in the e-form. 
It will be obvious from these statements that it is all-important to 
determine the nature of the product, both when condensation is effected by 
ordinary chemical means and also when effected by means of an enzyme. 
1. Proof is given in the present communication that when the condensa- 
tion is effected under laboratory conditions the action takes place in the 
manner indicated above; in other words, the two products required by theory 
are both formed. 
2. Evidence is adduced to show that isomaltose is the @-glucoside correlative 
with the a-glucoside maltose. | 
o. Experiments are described bearing on the formation of isomaltose by 
the agency of the a-enzyme maltase and of its correlative maltose by the 
agency of the @-enzyme emulsin which leave little doubt that the two 
bioses are producible from glucose. 
4. And whilst it is left undecided whether maltase can give r.se to 
maltose, evidence is cited which at least renders it probable that emulsin does 
not give rise to isomaltose. 
Synthesis of Maltose and Isomaltose by means of Chlorhydric Acid. 
To effect the condensation of glucose, E. Fischer used ordinary chlorhydric 
acid. The precipitate obtained on mixing the liquid with a large quantity of 
alcohol and ether was dissolved in water and all fermentable matter was 
removed from the neutralised solution by means of brewers’ yeast. Such a 
method of purification would have destroyed any maltose which had been 
formed. Fischer does not appear, however, to have contemplated the 
formation of this sugar. } 
In my experiments, a stronger acid was used and this was afterwards 
removed by means of lead carbonate. Appropriate yeasts were used to 
destroy one or the other carbohydrate. 
One hundred grammes of glucose having been dissolved in 300 cc. of 
concentrated chlorhydric acid, the mixture was cooled to 0° and hydrogen 
chloride gas was passed in until the colour commenced to darken. The 
liquid was kept below +10° C. during about 40 hours, when the temperature 
was allowed to rise to 15°. After neutralising the acid by stirring the liquid 
with lead carbonate, the filtrate and washings were shaken with silver 
carbonate to remove the dissolved lead chloride. 
Finally an almost colourless neutral solution was obtained. Judging from 
* © Roy. Soc. Proc.,’ 1904, vol. 73, p. 5388. 
