F. H.. Storer—Ammonia a contaminant of Sulphuric Acid. 445 
Those substances, such as sulphate of soda for example, 
which contained no ammonia when taken from freshly opened 
bottles, likewise contained none when taken from bottles that 
general I have not observed that chemicals taken from their 
bottles at the moment of reaching the laboratory are any more 
hable to be free from ammonia than those which have been 
long in store. 
_ A good idea of the relative importance of the ammonia found 
mm the chemicals above described may be got by contrasting the 
figures given in the table with the amounts of ammonia that 
occur in natural waters as given by Wanklyn and by man 
other authorities, or by comparing the above results obtained 
from chemicals with the following statement of results that 
were obtained from rain water in this laboratory at the same 
ume and by the same operator. ; 
One litre of rain water taken from 
south cistern of Bussey Inst. 
Coistanaad ms of 100 c. c. of the water 
bumenoid contained 
> Free NH4. ammonia. free 3. 
April 20, 1875, 532 “08 070000532 
April 20, 1875, 532 06 070000532 
April 22, 1875, -480 07000048 
May 4, 1875, 500 10 000005 
June 7, 1875, “480 Pee 0°000048 
June 7, 1875, 475 ame 0-0000475 
One litre of rain water caught in 
dish on roof of Bussey Inst. 
July 23, 1875, 10 jeg 0-00001 
July 29, 1875, 30 aa 000003 
One litre of rain water from 
SHOW ca 
April 20, 1875, "147 06 00000147 
—such as sold hereabouts, as in all American towns, for 
omestic use—is remarkably free from ammonia. Thus a litre 
of water obtained by melting a block of Muddy Pond ice was 
found to contain only 013 milligram of ammonia. In other 
words, 100 cc. of the melted ice contained no more than 
It is worthy of mention that water obtained by melting i 
