248 
Proceedings of the Royal Society of Edinburgh. [Sess. 
those previously considered — the most effective part of the temperature 
scale in producing “ sensitive state ” being for it 150 c -200° C., instead of, as 
Fig. 2. 
(a) Percentage sensitive state due to rise of temperature. 
( b ) >> ,, ,, fall ,, ,, 
(<0 ,, rise and fall of temperature. 
in all the other cases, 100°-150° C. As might be expected, 100 c -200° C. is 
still the most sensitive interval for rises of 100°. While the (a) curve for 
this specimen (fig. 2 (ii.)) resembles that previously shown in rising to a 
maximum value (of only 13 per cent., however) about 200°, and then falling 
