Career
In his business activities, he made several metallurgical and mechanical advancements, the most notable being a process for creating stable bars and other usable forms of iridium. The family settled in Cincinnati, Ohio, where he stayed for the rest of his life. He served an apprenticeship, then worked for the pen maker George West. Sheppard.
In 1862, he acquired the entire business and quickly expanded lieutenant
In 1880, Holland discovered the ability to melt and make castings of iridium by fusing the white-hot ore with phosphorus, and patented the process in the United States. He invoked the help of William Lofland Dudley in getting rid of the phosphorus, who did so by repeated applications of lime at great heat.
This is the first reported method of refining iridium. Dudley then found new applications for iridium, and formed the American Iridium Company with Holland.
After John Holland"s death in 1917 the company started to decline, and was closed around 1950.