The $J=0\ensuremath{\rightarrow}1$ rotational transitions of TCl and TBr have been measured at 1.36-mm and 1.74-mm wavelengths, respectively. These measurements, with ${\ensuremath{\alpha}}_{e}$ and $D$ from infrared data, yield the following constants: For tritium chloride, For tritium bromide, From the TBr measurements and similar measurements on DBr made previously in this laboratory, the mass ratio $\frac{{m}_{T}}{({m}_{D})}=1.49747$ was obtained.

Reports concerning the level of antitoxin in persons below which a Schick test elicited a positive reaction and above which, a negative one, are discussed.