TRANSACTIONS OF SECTION I. 555 
Methods.—The animals employed were dogs, cats, and monkeys. The 
momentum of a glass rod 8 mm. in diameter weighing 50 grammes falling upon 
the exposed cord, or upon the superficial surface of the laminze of the upper 
lumbar vertebr, caused the concussion. Motor and sensory conduction in the 
cord was tested at varying intervals after the production of the concussion. 
It was found that very slight injuries of the exposed cord produced marked 
alteration in the conduction, although the anatomical changes demonstrable in 
the cord after such injuries were very slight. Alteration of conduction in the 
spinal cord can be produced by a concussing force directed upon the superficial 
surface of the spinal column, although no macroscopic change in vertebral 
structure is produced. After the abolition of motor efferent conduction afferent 
conduction can still be demonstrated. 
SYDNEY. 
FRIDAY, AUGUS?' 21. 
Demonstrations by Professor Sir T. P. ANDERSON SruaRT. 
The Cyclograph, an Instrument for quickly marking Microscopical Slides. 
The Action of the Stapedius Muscle. 
) 
b) An Apparatus for illustrating the Nature of Sound Waves in Air. 
) The Effect of Simultaneous Contraction of the Intercostal Muscles. 
is} 
The following Papers were then read :— 
1. Climate from the Physiological Point of View. 
By Professor W. A. OsBorRNE. 
The theory of wet-bulb temperatures in their relation to body temperature we 
owe to Haldane. Harrington had already surmised their importance, and had 
mapped the United States with wet-bulb isotherms for the month of July. In 
estimating climatic conditions in Australia, in so far as they affect the body, 
the wet-bulb isotherms are extremely useful. There are, however, certain 
limitations in the use of this method. I have found that the wet bulb is not 
nearly so responsive to change in wind velocity as the human body. A typical 
instance of this is seen when a hot dry north wind in Victoria gives place to a 
cool southerly breeze with or without electrical disturbance and rain. The 
wind drops, the sky becomes overcast, and a feeling of oppression is experienced, 
whilst visible sweating may be more readily provoked. Owing to the over- 
clouding the shade dry-bulb temperature has fallen, and in nearly every 
instance the wet bulb has fallen too. If, however, a wet-bulb thermometer 
is employed, the bulb of which is surrounded by a cage covered with some 
closely woven fabric, it is found to be much more sensitive to wind velocity 
than the naked wet-bulb thermometer. Such a thermometer, too, shows in a 
‘change’ an increase in the height of the mercury column during the oppressive 
period before the cool breeze. ‘These ‘ jacketed’ wet-bulb thermometers I have 
made with a cylindrical cage of copper-gauze covered with fine-mesh bolting- 
cloth. Unfortunately the cloth soon becomes greased and clogged. Two or 
three ply of fine copper-gauze will act fairly well instead of the bolting-cloth, 
but here, too, the apertures become filled and readings lack constancy. I have 
been compelled to fall back on quite impervious material in the form of a hollow 
cylinder, open below, but having a perforated stopper of cork above, through 
which the thermometer stem passes. The bulb with its usual cotton covering is 
placed in the centre of the cylinder. In this instrument a considerable degree of 
sensitiveness to change of air velocity can be demonstrated. It will frequently 
show a rise at the onset of a thunderstorm when the ordinary wet bulb gives a 
fall. 
