xxxii. New Zealand Institute. 
a poisonous compound which when in large quantities causes sickness 
and death, we can realize how vastly important the absence of smoke 
may be to the health of future generations. 
At the same time it must be admitted that gas has as yet not been 
fairly treated; it has been regarded almost entirely as a means of 
lighting, not sufficiently as a means of heating, and hardly at all as a 
motive-power. Dr. Siemens (who has protested strongly against this 
mistake) confidently predicts that, before many years have elapsed, we 
shall find in our factories and on board our ships, engines, with a fuel 
consumption not exceeding llb. of coal per effective horse-power per 
hour, in which the gas-producer takes the place of the present steam- 
boiler. 
With regard to electricity as a motive-power, electric railways are 
already in existence in Ireland and in Germany ; but scientific men 
seem of opinion that, except in cases in which natural sources of 
energy, such as hills and waterfalls, are found, it will be long before 
electrie power can take the place of steam on ordináry railways. I 
need not point out, however, that this is a country in which such 
sources of energy abound everywhere. I trust that at no distant 
day the force which is now applied in the form of friction necessary 
to hold back the trains in their descent of the Rimutaka Hill, 
and which is now dissipated and lost in wear and tear, may be utilized 
for propelling the engines for miles of their journey along the level 
country. 
Whilst speaking of scientific discoveries as applied to practical 
matters, I cannot leave unmentioned a process which, though ex- 
' tremely simple in itself, is likely to mark an era in the history of 
the colony, and greatly to increase its wealth. I refer to the freez- 
ing of meat, and other products which might perhaps be similarly 
treated. I may mention, in passing, that the object of the process is 
not, as might have been supposed, tv change the temperature 
of the atmosphere, but to suspend the vivifying powers of the 
germs which are continually floating about in it. As Professor 
Tyndall has pointed out, in his lecture before the Royal Institution 
in 1877 and elsewhere, animal matter may remain uncorrupted for 
months exposed to the air, provided that air is rendered perfectly 
free from these germs; whereas the slightest contact with air 
in its ordinary impure state—a mere pin-hole in the vessel contain- 
ing the clarified atmosphere, for instance—admits the germs, and 
corruption ensues. The attempt to exclude the atmosphere from 
meat during the passage to Europe has been made, and has been 
found impracticable; but the desired result has been obtained by 
chilling the air to such an extent that the vivifying power of these 
germs is suspended. 
