TRANSACTIONS OF SECTION B. 759 
properly greased. If necessary it can be made perfectly secure by means of 
platinum wire. The total weight of the apparatus when fully charged is 58 to 
60 grms. 
Mr. J. Towers, of Widnes, has undertaken to supply the apparatus. 
7. A new Form of Aspirator. 
By Cuartes A. Koun, Ph.D., B.Sc., and T. Lewis Barney, Ph.D. 
The aspirator consists of a reversed gas meter worked by a small electric motor, 
and is specially adapted for aspirating large quantities of gas, such as are required 
for the determination of sulphur dioxide in air. A series of three cog-wheels are 
fixed to the axle of the drum of a wet gas meter, to which a ‘ Porter’ motor is 
attached, which is run by a single secondary cell with a capacity of 25 ampere 
hours. The drum revolves twice per minute, the gearing being so arranged that 
about 15 cubic feet of air or other gas can be drawn through the absorbing tower 
or other apparatus per hour. The advantage of this form of aspirator is its even- 
ness and continuity. The single cell is sufficient to run the meter for thirty hours. 
TUESDAY, SEPTEMBER 22. 
The following Papers and Report were read :— 
1. The Detection and Estimation of Carbon Monowide in Air. 
By Dr. J. HAupane. 
This method for the determination of small percentages of carbonic oxide in 
air depends on the following facts :— 
Hemoglobin, the colouring matter of blood, readily combines to form similar 
compounds with both oxygen and carbonic oxide. Both compounds are disso- 
ciated in a vacuum, but the carbonic oxide compound (6r carboxyhemoglobin) 
is much more stable than the oxygen compound (or oxyhemoglobin), In presence 
of a gas mixture containing both oxygen and carbonic oxide a mixture of carboxy- 
hemoglobin and oxyhzemoglobin is formed; and the proportions in which the 
hemoglobin divides itself between the oxygen and carbonic oxide depends on the 
ratios of the percentage of oxygen to that of carbonic oxide multiplied by a 
constant. Hence if the percentage of oxygen in the gas mixture be known, as in 
the case of ordinary air, the percentage of carbonic oxide can be inferred if the 
proportions be known in which hzemoglobin brought into contact with the mixture 
divides itself between the two gases. Now, it is extremely easy to determine these 
proportions colorimetrically by taking advantage of the fact that in dilute solution 
carboxyhmoglobin has a pink colour, while oxyhemoglobinis yellow. By adding 
a certain amount of dilute carmine solution to oxyhzmoglobin solution, the tint 
of carboxyhemoglobin solution can be exactly reproduced. In the case of a 
mixture of oxyhemoglobin and carboxyhemoglobin, the less the proportion of the 
latter present the less will be the amount of carmine required; and from the 
amount of carmine needed the proportion of carboxyhzmoglobin can easily be 
estimated. 
The author then described the process in its simplest form. A solution of blood 
is first prepared of such strength as to show the difference of tint between oxy- 
hemoglobin and carboxyhsemoglobin ; a suitable dilution can easily be guessed from 
the depth of colour, About 1 in 100 is very good. A solution of carmine of a 
corresponding or slightly greater depth of colour (about ‘01 per cent.) is also pre- 
pared. The carmine is dissolved in a minimum of ammonia, and then diluted down. 
_ The sample. of air to be examined should be collected in a small, dry, and 
clean bottle of 100 or 200 c.c. capacity, and closed with a cork soaked in paraffin 
wax. This bottle is opened under the blood solution in a basin, and about 5 c.c. 
of air allowed to bubble out, so as to introduce a corresponding quantity of 
