268 Nitrogen in Organic Compounds. 
Besides substances destitute of nitrogen, many that contained 
but a small quantity of nitrogen were experimented with, and al- 
ways a larger quantity of ammonia was obtained than was due to 
the nitrogen present in the substance. 
M. Reizet has also found that the mixture of alcohol and ether 
used, decomposes a small quantity of the bichloride of platinum, 
which is always added in excess, so as to form a small quantity 
of the protochloride, which being insoluble in this menstruum, is 
only a cause of error. 
From these experiments, M. Reizet concludes that MM. Varren- 
trapp and Will’s method should be used with great reserve, when 
new substances are the subjects of analysis, but he does not doubt 
that in the hands of skillful manipulators, it might become a valu- 
able means of control. 
The contents of this letter should have been communicated to 
you before, but I have been for some time intending to try a 
modification of this method, which suggested itself to me, asa 
means of remedying the defects pointed out by M. Reizet, but 
my occupations have prevented me from testing this modification, 
and as it is impossible for me to say when I shall be able to per- 
form the necessary experiments, I have to content myself, in 
bringing it to your notice simply as a suggestion. 
First, then, in preparing the mixture of potash and lime, after 
we have heated the mixture for the purpose of drying it, while 
hot, place it beneath a vessel containing oxygen gas, which gas 
will become condensed in the pores of the mixture, and prevent 
the nitrogen of the air finding its way in, when exposed to the 
atmosphere. Oxygen is preferred to hydrogen gas, from the fact 
that the former would be absorbed in larger quantity, and more ef- 
fectually exclude the nitrogen. Thus much then for the prepara- 
tion of the mixture. When employed, it is to be mixed with the 
substance to be analyzed, introduced into the tube, and the air of 
the tube is then to be driven out either by oxygen or hydrogen 
gas; if these precautions are taken, which will certainly not be 
found difficult of application, I doubt not that all error arising 
from the nitrogen of the air would be avoided. 
Charleston, S. C., April 12, 1843. 
Messrs. Editors—I have just received the January number of 
the Annalen der Chemie und Pharmacie, and there find an arti- 
