( 120) 
and from (6) and (7) 
Ante 15 3 
end Rd Mac! i 
In the subjoined table are given for a few capillary electrometers, 
examined without purposely inserted resistance the values of A, 
and A» in percentages of A. 
Des is En oeh 
Baier of ie 100 x A, | 100 x A, 
capillary. | d a 
\ 
G. 103 91 9 
B AOL 92 8 
B. 102 | 93 7 
B. 103 96 4 
In the course of these experiments valuable assistance has been 
given by Mr. H. W. Buére and Mr. H. K. pr Haas. 
Botanics. — Prof. BriJERINCK speaks: “On the Formation of Indigo 
from the Woad (Isatis tinctoria)” '). 
Some years ago I wished to become acquainted with the so-called 
“indigo-fermentation”, about which nearer particulars had been 
communicated by Mr. Arvarrz. He examined Indigofera and says:”). 
“If a decoction of the plant is prepared and sterilised atfer 
passing it into test-tubes or PAsTEUR’s-flasks, the reddish colour of 
1) It was first my intention to treat „On the function of enzymes and bacteria 
in the formation of indigo” I have declined this plan for the moment, and give now 
only part of my experiments, because I see that also Mr. HAZEWINKEL, of the Experi- 
mentstation for Indigo at Klaten, Java, has obtained important results about that 
very subject, which results, for particular reasons, have however been imparted till now 
to a few experts only. Yet I cannot avoid mentioning some facts, found by me, tke 
priority of which perhaps pertains to Mr. HAZEWINKEL, without my being able to 
acknowledge his claim. One indiscretion, however, I am obliged te commit: Mr. Haze- 
WINKEL has, already before me, established the fact, that by the action of the indigo- 
enzyme and of acids on indican, indoxyl is produced. 
2) Comptes rendus T, 105, pag. 287, 1887. 
