BY DR. OSCAR KATZ. 329 



some deliberation, I decided to employ for this purpose a Miiller's 

 " Alpha Patent Gas-making Machine." 



This apparatus produces gas in the shape of a mixture of atmos- 

 pheric air and the vapour of gasolene or petroleum spirit (composed 

 of carbon and hydrogen) ; this mixture is called " air-gas." By 

 means of weights, atmospheric air is pumped through a drum into 

 a chamber, where it becomes impregnated or " carburetted " with 

 the vapour of that very volatile liquid. It is thus turned into gas j 

 as such it passes into a small gasometer ("governor "), "whence it 

 supplies automatically what is required for the burners, no matter 

 how many are in use." 



The machine used by me was a so-called 40-light one, in other 

 words, one able to yield 200 cubic feet of gas per hour, A sub- 

 stantial little house, adjoining the laboratory, was specially built 

 for it ; this house also contained the store gasolene. Pipes were 

 conducted all through the laboratory ; the gas was employed both 

 for heating and lighting. 



My experience with this gas — I know it now for nearly a year 

 — -goes to show that it is, on the whole, well adapted for labora- 

 tory researches in cases where coal-gas cannot be easily obtained. 

 The whole apparatus requires only little room ; the processes of 

 filling in fresh gasolene, or of winding up the weights, take but 

 little time. The knowledge of the way in which the machine 

 works, and how it will give satisfactory results, must, of course, be 

 acquired.* 



It speaks well, I think, for the gas manufactured in the above- 

 stated manner, that by aid of some thermo-regulator, and a little 



* For a proper evaporation of the gasolene, it is necessary that the gas- 

 making machine should be kept at not too low a temperature. In a climate 

 such as that of Sydney, the prevailing temperatures all through the year 

 are favourable to the manufacture of "air-gas." In colder places, in winter 

 it will become necessary to arrange for special heaters in the gas house. 



