432 SECTIONAL TRANSACTIONS.—I. 
for the deaf. Various types and degrees of deafness were included in the 
group. 
Some theoretical considerations especially with regard to the education 
of deaf children. 
GENERAL DISCUSSION (12.20). 
AFTERNOON. 
Excursion to the Cider Works of Messrs. Wm. Gaymer & Son, Attle- 
borough (2.7). 
Friday, September 6. 
Mr. 'T. W. Apams and Dr. E. P. Poutton.—Some further applications of 
a new study of heat production in man (11.10). 
At the Aberdeen Meeting we showed that the output of CO, was the 
measure of the amount of combustion in the body, while the oxygen intake 
was a resultant of combustion and conversion. There was no time to bring 
the further conclusions of our study before the Section, but these appear 
in the Report for 1934. 
Some results of Benedict and Milner throw an interesting light on the 
metabolism of muscular work, which is a perplexing problem, because the 
respiratory quotient is above unity when the work is extreme. Since 
Krogh and Lindhard’s experiment (1919) it has been generally accepted 
that with muscular work on a carbohydrate diet the CO, is greater and the 
O, less than on a fat diet, which might mean that more carbohydrate was 
being oxidised, and they argued that with fat more heat was produced ; but 
in the similar experiments of Benedict and Milner (1903-4), who used a 
respiratory calorimeter, the measured heat was the same on the two diets. 
When the three hourly results are analysed it is necessary to assume that there 
is some kind of partial reduction of carbohydrate towards fat of a temporary 
nature. The results for the whole period suggest either that more carbohy- 
drate was oxidised on the carbohydrate diet or, as we prefer to think, that 
carbohydrate and fat were oxidised in a fixed proportion, and carbohydrate 
was also converted into fat. 
Dr. F. W. Eprmpce-Green, C.B.E.—The colour of the positive after-image 
of a colour (11.30). 
In certain conditions the colour of the positive after-image of any colour 
or white is purple. It is best to use only one eye, and to have both eyes 
covered with a black cushion before performing the experiment. The 
object should then be viewed for the shortest possible time and the black 
cushion be replaced over the eye. If tried with a spectrum the whole of 
the after-image becomes purple. if ona piece of white cardboard eighteen 
inches square a series of small squares of red and blue cardboard, each 
about three-quarters of an inch square, be pasted to cover a surface of about 
nine inches square, be placed in sunlight and viewed as previously mentioned 
at a distance of three feet a brilliant positive after-image, red, blue and 
white, will be seen for a fraction of a second; then all changes to purple, 
which becomes brighter and then disappears from without inwards in about 
eight to twelve seconds without becoming negative; the last thing to be seen 
oy 
