8 
of Paste 100 feet per second, while light travels 200,000 miles a 
second. 
Saccharine, or to give it its due title of ‘‘ Benzoilsulphonicionide,”’ 
was at first hailed as likely to be of great use in many departments 
as a powerful sweetening agent, but many tests have proved that 
there is little chance of its driving the sugar industry from the field 
asa regular article of diet. It is prepared from one of the consti- 
tuents of coal tar, and though in no sense a sugar, it possesses 
immense sweetening properties, one grain being sufficient to sweeten 
70,000 grains of water. It undergoes no change and does not 
ferment in the system, and is therefore invaluable in some cases of 
disease; it may also be used to disguise some noxious drugs, having 
a distinct flavour of its own. It can also be used with advantage 
in making jam, from its absence of fermenting properties; jam 
which has been prepared with saccharine is perfectly free from 
fermentation, though expesed to intense heat, months after its 
manufacture. On the other hand it has not so agreeable a flavour 
as fruit sweetened by sugar. Moreover it will never be used for 
confectionery, from which the maker derives his profit by weight ; 
the quantity and weight of saccharine used in a given quantity of 
sweetmeats being infinitesimal, whereas the cost has been even 
greater than that of sugar. One can hardly wish that such a vast 
field of industry as that of sugar cultivation should be abolished in 
favour of a substance produced in the laboratory ; it would entail 
terrible loss on thousands of all classes. Lastly the profession to 
which I have the honour to belong is by no means unanimous as to 
the benefit of exchanging a nutritive article of diet like sugar, for 
one which passes unchanged through the body, excepting, as I have 
said, in some cases of disease. 
Another manufacture of possibly great commercial value, is that 
of artificial silk. M. de Chardonnet has produced this by various 
chemical solutions filtered and forced by pressure through a fine 
tubular orifice, and which issue as a semi-solid thread, which, 
when solidified by the air, may be wound like the silk from a cocoon. 
The thread is supple, transparent, and silky; it is grey, or black, 
but can be died. Cotton or other materials covered with a film of 
this artificial silk, may serve as the basis of beautiful fabrics. I 
must not leave this part of my address, which will specially interest 
the feminine portion of my audience, without paying a tribute to 
their infallible instinct with regard to scientific matters. Sydney 
Smith defined a woman as “a biped who refused to reason, and 
who lit a fire from the top.” It is, however, conclusively proved 
that the scientific method of preventing smoke, and economising 
fuel when lighting a fire, is by doing so from the top. In this way 
the hydro-carbon vapours from the coal pass through the fire above, 
