The gases collected for laboratory examination were tested especially for carbonic acid (CO_{2}), illuminating gas, oxygen (O), carbonic oxide (CO), and nitrogen (N). The method of examination employed was that generally followed in gas analysis, namely, the absorption of the gases by liquid reagents. Carbonic acid was absorbed by potassium hydrate; illuminants by bromine; oxygen by phosphorus; and carbonic oxide by cuprous chloride dissolved in hydrochloric acid. The estimated amounts of the gases enumerated above are as follows, the values indicating the parts of a cubic inch to the gallon; the estimated water being also included in the table:— ┌─────────────────┬──────┬──────┬────────────┬─────┬─────┬────┐ │ │H_{2}O│CO_{2}│Illuminating│ O │ CO │ N │ │ │ │ │ Gas. │ │ │ │ ├─────────────────┼──────┼──────┼────────────┼─────┼─────┼────┤ │Before Cremation,│ .0011│.00080│ .000│.0080│.0000│.016│ │During Cremation,│ .0044│.00091│ .012│.0065│.0017│.015│ └─────────────────┴──────┴──────┴────────────┴─────┴─────┴────┘ It will be seen by a comparison of these results that the gaseous products of ordinary coal combustion are modified to only an inconsiderable extent by matter passing through the walls of the cremation retort. Illuminating gas is a variable mixture of hydrogen, marsh gas, olefiant gas, and other gases, and is entirely harmless when produced in the small quantities indicated in the table, and so thoroughly distributed through the air. That so much free oxygen passes off with the escaping products is an indication of the thoroughness of the combustion, and the complete oxidation of the oxidizable products. In conclusion, I would say that not any of the many and various tests, either at the crematorium or in my laboratory, of the products under consideration, indicated the presence of anything that would pollute the air. The burning of the body produces no material difference in the gases escaping from the chimney. The volume of the chimney products did not seem to be increased by the burning of the body, and the products had precisely the same odor during cremation that they had before the body was put in the retort. I might add that I also made a test of the temperature of the products issuing from the chimney, and found it to be about 300° F. This is surprisingly low, considering the high temperature of the retort (2500° to 2800° F.), and indicates a most excellently designed furnace, utilizing as it does so large a percentage of the heat. About one-fourth of the heat of boiler furnaces goes up the chimney.