Gooch and Clemons—Selenious Acid, ete. 51 
There are enormous masses of pitch within the lake that could 
not in my opinion be distinguished by the eye, from the pitch 
taken from village lots by either of the companies before 
mentioned. Iam therefore quite at a loss to determine why 
Mr. Richardson alleges such a specific distinction between 
what he is pleased to term “lake” and “land” asphalt. It 
appears to me to be a distinction without a difference. 
For further facts concerning the commercial and economic 
relations of Trinidad Asphalt, the reader is referred to the 
report of Consul Pierce, which I believe to be one of the most 
complete and impartial of all the valuable consular reports 
issued by the State Department. 
It was my intention to include in this paper some statistics 
regarding the enormous amount of asphaltum of different 
varieties shipped from La brea since January Ist, 1890. 
When a friend applied to the custom house in Port of Spain 
for an official statement, he reported that such information had 
been refused, on the ground that such a statement would make 
public private interests, inasmuch as the Trinidad Asphalt 
Company had shipped several cargoes of “land pitch” to the 
United States since that date. 
_ By referring to the maps the reader can clearly distinguish 
_the relative positions of the lake and the adjacent portions of 
the island. 
University of Michigan, Ann Arbor, Michigan, April 15th, 1895. 
Art. V.—The Determination of Selenious Acid by Potassium 
Permanganate; by F. A. Goocu and OC. F. CLEMONS. 
[Contributions from the Kent Chemical Laboratory of Yale College—XL. ] 
Tue fact that sulphurous and tellurous acids may be oxidized 
quantitatively by a sufficient excess of potassium permanganate 
suggests naturally the application of the same general method 
to the determination of selenious acid. It is the object of this 
paper to record the results of experiments in this direction. 
Brauner* found that in the action of the permanganate upon 
tellurous acid, whether in a solution acidified with sulphuric 
acid or made alkaline by caustic soda, the reduction of the per- 
manganate does not proceed to the lowest degree of oxidation, 
the tellurous acid being unable to reduce the higher hydroxides 
of manganese which separate. In employing the reaction 
quantitatively it is necessary, therefore, to add the permanga- 
nate in distinct excess and then to destroy the surplus by means 
* Jour. Chem, Soc., 1891, p. 238. 
