522 Proceedings of Royal Society of Edinburgh. [sess. 
Percentage Free Acid. 
Concentration 
of Acid Sulphate. K. Na. Li. NH 4 Mg. 
0125 (Ostwald: Action on zinc sulphide) 79 82 — 91 93 
01 (Kay : Catalysis of ethy lie acetate) 71*8 73'2 73*6 72*6? 79‘4 
0’2 (Trey: Catalysis of methy lie ,, ) 63‘6 64*0 64*6 — 71 '4 
I have also added a series calculated from Trey’s measurements 
of the rate of catalysis of methylic acetate. With the exception 
of one very uncertain value for ammonium acid sulphate, the three 
horizontal columns show the same arrangement throughout. 
This research was carried out during the winter 1897-98 in the 
physico-chemical laboratory of Stockholms Hogskola, Stockholm. 
I should like to avail myself of the opportunity to express my 
warmest thanks to Professor Arrhenius for the valuable assistance 
which he so willingly gave me, and for the interest he took in my 
work. 
