PROPER film splicing should be done automatically. It was found that there is no difference in strength between the 0.156inch and the o.o78-inch splice. The use of a proper scraper with a square edge is recommended.
Time increases the strength of splices, but this effect may be replaced largely by heat. Excess use of cement should be avoided because it causes buckling and warping. A "BUBBLER" LABORATORY FRACTIONATING COLUMN.' By H. T. Clarke and E. J. Rahr.
_A_ NEW type of laboratory distillation column in which the ascending vapor is washed by the reflux liquid in bubbling traps on the counter-current principle.
This column, which is constructed entirely of glass and contains no movable parts, may readily bc made by an amateur glass-blower.
Liquids can bc separated more rapidly with this apparatus than with 'the usual forms of laboratory column. Thus on distilling a mixture of two litres each of commercial benzene and toluene through a still head containing eight bubbling traps, 148o c.c. of benzene boiling at 79-82 ° was obtained in seven and a half hours, while on continuing the distillation the residue boiling above lO9 ° amounted to 1455 c.c.