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TUESDAY, MAY 1st. 



A Lecture on " Heating and Cooking by Gas," was delivered 

 by Dr. H. E. Armstrong, F.R.S., Sec. Chem. Soc. 



Gaseous fuel, such as ordinary coal gas, has both its advantages 

 and disadvantages from a domestic point of view. Thus it may 

 be burnt without the production of smoke or dust ; a gas fire may 

 be lit at any moment, whenever required ; it entails no labour ; it 

 need not be kept burning any longer than is requisite ; and it 

 attains its full efficiency very soon after it is lit. But it is very 

 costly in comparison with coal or coke, and its use undoubtedly 

 involves the exercise of more intelligence than is commonly dis- 

 played in burning coal. 



Coal gas chiefly consists of hydrogen and marsh gas mixed 

 with carbonic oxide and small quantities of hydrocarbons (com- 

 pounds of carbon with hydrogen), which are the main source of its 

 illuminating power. \Mien allowed to bum freely in the air, its 

 constituent gases undergo complete combustion, water and carbon 

 dioxide (carbonic acid) being formed ; but if the air supply be 

 insufficient, or even if an ample supply of air be provided and the 

 gas be burnt under a cold surface, such as that of a metallic vessel 

 containing water, the combustion is always more or less incomplete, 

 and carbonic oxide and acetylene are formed. These two last- 

 mentioned gases are highly poisonous ; their production in this 

 way has led to not a few fatal accidents and has involved Ulness 

 probably in very many unsuspected cases. The so-called "Geysers " 

 are specially dangerous, ana the statements often made by vendors 

 that in their stoves the combustion is complete should not be 

 believed. Hence, gas should never be used for heating purposes 

 unless efficient means be taken to carry away the products of 

 combustion, and under no circumstances should a gas stove be used 

 unless provided with a flue. In order to secure efficient ventilation 

 of bath rooms, &c., it is not only necessary to provide an exit ; an 

 inlet for fresh air must also be provided, otherwise the supposed 

 exit will rarely act but as an inlet. 



Various forms of gas heating stoves were referred to, and it 

 was pointed out that the chief defect in all arose from the difficulty 



