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Josiah Marshall Heath (c1795-1851)
1795 Possibly born in Ireland the son of Rear-Admiral Heath and his wife Rebecca Marshall
1805 Listed as commercial agent at Coimbatore 
1816 Married Charlotte Catherine the youngest daughter of General Charles Fraser at Mount Capper Villa, Madras 
1825 Heath, then of the Madras Civil Service, obtained from the East India Company exclusive right to the large scale manufacture of bar iron in the Madras Presidency. Works were established at Porto Novo (Parangipettai). Eventually high quality bar iron was produced and significant quantities exported to Britain. However, for a variety of reasons, the venture was a commercial failure. Heath had returned to Britain by 1837 
1825-29 Back in the UK where he brought samples of Indian Ore to David Mushet
1833 Erected blast furnaces and a forge 
1839 Heath introduced the use of manganese in steel-making 
From The Mining Journal, 1857 :-
'In 1839 comes the important invention of Josiah Marshall Heath for the manufacture of iron, and which, as regards steel, was as great a stride in the manufacture as compared with any previous process as the process of Uchatius is at the present time. The duration of this patent was, after much litigation, prolonged, by an application to the privy council, for seven years. Although the principle of Heath’s invention had been previously described, and even as early as 1799 William Reynolds patented the employment of oxide of manganese or manganese in the conversion of pig iron into malleable iron or steel, but gave no proportions of details, it appears that until the introduction of Heath’s patent no practical results were arrived at.'
From 'The Beginnings of Cheap Steel', by Philip W. Bishop: 'The work of Reaumur and, especially, of Huntsman, whose development of cast steel after 1740 secured an international reputation for Sheffield, had established the cementation and crucible processes as the primary source of cast steel, for nearly 100 years. Josiah Marshall Heath's patents of 1839, were the first developments in the direction of cheaper steel, his process leading to a reduction of from 30 to 40 percent in the price of good steel in the Sheffield market. Heath's secret was the addition to the charge of from 1 to 3 percent of carburet of manganese as a deoxidizer. Heath's failure to word his patent so as to cover also his method of producing carburet of manganese led to the effective breakdown of that patent and to the general adoption of his process without payment of license or royalty. In spite of this reduction in the cost of its production, steel remained, until after the midpoint of the century, an insignificant item in the output of the iron and steel industry, being used principally in the manufacture of cutlery and edge tool.' 
From Sir Henry Bessemer: '....From the foregoing long list of claimants to the use of manganese in various ways in steel making, it must be evident that a knowledge of its beneficial effect was widely known and highly appreciated nearly a century ago ; but the most prominent, and the most practically successful, of all these patentees was a Mr. Josiah Marshall Heath, a civil servant under the Indian Government, who, noticing in the native Wootz steel-making of India the marvellous effect of manganese, conceived the idea of producing steel of superior quality from inferior brands of British iron by its use in the cast-steel process then extensively carried on in Sheffield. Heath came over to this country, and obtained a patent, bearing date the 15th of April, 1839, for the employment of carburet of manganese (that is, manganese in the metallic state) in the manufacture of cast steel : an invention of very great utility, as by lts use cast steel of excellent quality could be produced from British iron that had been smelted with mineral fuel. Such steel possessed the property of welding either to itself or to malleable iron. The Sheffield cutlers were thus enabled to weld iron tangs on to the cast-steel blades of table-knives, and also to weld many other similar articles : a process which was not successfully carried on previous to the use of metallic, or carburet of, manganese under Heath's patent.
Mr. Heath, in his specification, does not confine his claim to the use of carburet of manganese in crucible steel melting, but distinctly claims "the use of carburet of manganese in any process whereby iron is converted into cast steel." All that Heath claimed lapsed and became public property when his patent expired, and the right to use carburet of manganese " in any process whereby iron is converted into cast steel" became common property by this publication, even if the patent were invalid. Heath was fully justified in making this general claim, because the results obtained depended on an inevitable chemical law, viz. : whenever metallic manganese, with its powerful affinity for oxygen, is put into molten iron containing disseminated or occluded oxygen, a union of the oxygen and the manganese follows as an inevitable consequence of their strong affinity for each other, wholly irrespective of the process employed in the manufacture of the iron or steel so treated.
In consequence of this successful invention of Heath's, no British iron that has been smelted with mineral fuel is ever made into cast steel in Sheffield without the employment of carburet of manganese. In the early days of Heath's invention, he supplied the carburet in small packages to his licensees ; he made this by the deoxydation of black oxide of manganese mixed with coal-tar, or other carbonaceous matter, in crucibles heated in an ordinary air furnace. This was a costly process, and as the demand increased he suggested to his licensees that it would be cheaper to put a given quantity of oxide of manganese and charcoal powder into their crucibles, along with the cold pieces of bar iron or steel to be melted. These materials would, when sufficiently heated, chemically react on each other, and produce the requisite quantity of carburet of manganese in readiness to unite with the steel as soon as the latter passed into the fluid state. But Heath's licensees said, "This is not precisely your patent, Mr. Heath," and they claimed the right to carry out this suggestion without paying him any royalty. This was the cause of some eight or nine years of litigation, by which poor Heath was ultimately ruined, although his patent was established by a final decision of the House of Lords alas ! only too late ; for Heath died a broken-hearted, ruined man, wholly unrewarded for his valuable invention.
Thus we see that both in the use of a carburet, and also by the use a mixed powder, consisting of oxide of manganese and carbon, Heath's process has been successfully and commercially carried on from the date of his patent, in 1839, up to the present hour. 
1851 February 4th. Died at Rectory Cottage, Hanwell? (in Brentford registration district) age 60 and buried Kensal Green Cemetery
His wife probably died at Bath in 1872 Q1.