CHEMICAL MANUPATURES IN GLASGOW, ETC . 
ART. XL. -ON THE MOST IMPORTANT CHEMICAL MA- 
NUFACTURES, CARRIED ON IN GLASGOW AND THE 
NEIGHBORHOOD. By Professor Thomas Thomson, of Glasgow, 
F. R. S. 
From the Transactions of the British Association/for the advancement of 
Science, for 1840. 
" Glasgow being the seat of a great many interesting and 
important chemical manufactures, it occured to me (said Pro- 
fessor Thomson) that it might be of advantage to those mem- 
bers of the chemical section, who have come from a distance, 
to give a short catalogue of the most important of these manu- 
factures, that they might know what the information is which 
they expect, and where they are to look for it." 
1. Iron. The smelting of iron has been practised in the 
neighborhood of Glasgow for more than fifty years; when the 
late Mr. Dunlap, of the Clyde Iron Works, first became pro- 
prietor of those works, perhaps the only one then in the 
vicinity, the product was only fourteen tons a week, or 728 
tons a year. At present the quantity of iron smelted in Glas- 
gow and the neighborhood, cannot be much less than 200,000 
tons, which approaches to a fifth part of the whole iron smelt- 
ed in Great Britain. The ore is very abundant all round 
Glasgow, and especially in the neighborhood of Airdrie? 
where the principal works are now situated. Fortunately 
, for the smelters, the iron-stone and coal-beds are associated 
together, the iron-stone either occurring in nodules or beds 
along with the coal. The rapid increase of iron smelting has 
been the consequence of a discovery of Mr. Neilson, manager 
of the gas works. This is now universally known under 
the name of the hot blast. The air is heated to more than 
607° before it enters the furnace, by passing through a range 
of heated pipes. Under this treatment it is found that the 
coal may be used without previous coking ; and that instead 
