34 JOURNAL AND PROCEEDINGS 
first portions of the distillate float on the water and constitute what 
is called the light soil. After a time substances of greater specific 
gravity pass over, which sink under water and constitute the heavy 
oil. From the light oil we obtain hydrocarbons, benzene and 
toluene. As these hydrocarbons form the basis of a number of 
important industries, they are separated from coal tar on a large 
scale. Starting with toluene, benzoyl, chloride is obtained by 
treating wth chlorine. This is converted into cinnamic acid. 
This dissolved in nitric acid yields ortho-nitro-cinnamic acid. 
Treated with alcoholic potash this is converted into ortho-nitro- 
phenyl-propiolic acid, which, on being reduced with sugar 
yields indigo. I don’t think I need say anything else to con- 
vince you that this is a purely chemical industry. Indeed, some 
of you may think that while the previous illustrations were ex- 
amples of chemistry applied to industry, this ought to be classed 
as an example of industry applied to chemistry. 
If time would permit, and I had the ability, I might show 
you how chemistry has been a benefit to industry in almost 
every line of human activity: how it has helped the farmer, 
showing him not only the value of rotation of crops, but exactly 
what are the best crops to sow in rotation; how it has helped the 
foundryman to make good castings, showed him what class of 
iron is suitable for light, thin castings like stove plates, sewing 
machines, ete., and what iron will give the requisite strength 
and toughness for engine beds; how chemistry has transformed 
the cement industry from a rule of thumb process to an exact 
scientific industry; how it has made gas mantles to improve the 
quality of lighting and decrease the cost; how it has purified 
sewage and in a thousand different ways been of benefit to the 
human race. I have shown you how substance, developed in 
the process of life, can be made in the laboratory; and some im- 
aginative chemists have pictured the time when meat, flour, 
coffee and food stuffs generally will be made artificially, in place 
of by the natural process of plant and animal life. And with 
the developments which have come in the short space of three 
generations, since Dalton enunciated the atomic theory, one 
must be bold indeed to set limits to the accomplishments of 
chemistry. 
