254 Wisconsin Academy of Sciences, Arts and Letters. 
tube and then the whole tube was filled with mercury. At the 
upper end of the longer leg was provided a pulley and bearing. 
The porous cup could be entirely closed, or provided with a 
reflux condenser. By means of a wire dipping into the top 
of the mercury column at (e) the current passed to the plati¬ 
num anode, through the electrolyte and porous cup, to the iron 
cathode (c). A thermometer was always kept in the beaker. 
Into the inner, or anode chamber of the apparatus, was in¬ 
troduced a solution of the following composition: H 2 0, 60 
cc.; alcohol, 50 cc.; KI, 20 g.; M 2 C0 3 , 6g. 
We regard the function of the electric current as that of 
primarily decomposing the KI, setting iodine free at the anode, 
and potassium at the cathode. The formation of iodoform is 
then the result of a series of secondary reactions which go on 
theoretically as shown by the following equations: 
A. CH 3 CH 2 0 + 21 = CH 3 CHO + 2HI 
CH 3 CHO + 61 = CI 3 CHO + 3HI 
CH 3 CHO + HOII = CHI 8 + HCOOH 
The iodine first oxidizes the alcohol to aldehyde, then sub¬ 
stitutes the three hydrogen atoms on one carbon atom forming 
the tri-iodo-aldehyde. This product in a weak alkaline, warm 
solution, breaks up into iodoform and formic acid. The pur¬ 
pose of the Ha 2 C0 3 is to neutralize the HI and HCOOH. 
The first trials with the above named electrolytes resulted as 
shown graphically by curve Ho. 1, Plate XI. Along the X 
axis were plotted ampere-hours and along the Y axis yields 
of iodoform in grams. Curve Ho. 2 is the corresponding cur¬ 
rent efficiency curve. Consideration of curve Ho. 1 shows 
us that to a certain point the yield of CHI 3 is approximately 
proportional to the number of ampere-hours. At point A, 
quite likely, the electrolyte had become depleted in one of the 
essential ingredients. The fact that the yield of iodoform is 
a linear function of the number of ampere-hours also suggests 
that there is a certain definite current efficiency. If a portion 
of the iodine liberated goes to form by-products, then this pro¬ 
portion of the whole amount of iodine liberated by the current 
is about constant under normal conditions. Curve Ho. 2 shows 
