Review: “Diamond Cut Diamond with a Vengeance”, William Hope Hodgson, 1918.
This is another crime story from Hodgson though the crime isn’t perpetrated by the protagonist, but he foils an attempt to steal industrial secrets he and his fiancé, Miss Gwyn, developed.
Tony Harrison and Nell Gwyn are Americans in London. A Jew, Mr. Moss, agrees to finance their experiments in producing diamonds artificially. The process takes about six months and starts with subjecting carbon to explosive pressure and then keeping it in a “pressure-box” for six months where it is very slowly cooled.
The two set up a lab on Cheyne Walk (the street that Hodgson’s Carnacki lives on though that is the only link to that series). The pressure-box is never unsupervised. Nell watches with her sister when Tony is out.
Moss takes to hanging out at the place when Tony is gone. He has a sexual interest in Gwyn. He confesses he really doesn’t expect the experiment to work. He just paid for it to get closer to Gwyn. He then starts pumping her for information on the process which indicates he does expect it to work. (After all, the story opens with a small diamond already produced in the process that Moss sees.)
Tony discovers the house is under surveillance, no doubt by Moss. In fact, he discovers Moss has rented the adjacent vacant row house. Tony finds that Moss has cut his gas supply off, hoping to ruin the experiment.
Tony cleverly foils an attempt by Moss to substitute a fake cylinder for the real one with diamonds. Tony substitutes his own fake cylinder for Moss to take.
The real cylinder is opened by Tony and Nell. The amount of diamonds is disappointing but still worth enough so that the couple can marry.
Moss gets his fake cylinder and fake formulas for the process.
In The Wandering Soul: Glimpses of a Life: A Compendium of Rare and Unpublished Works, Jane Frank says that science fiction scholar Samuel Moskowitz griped about the story’s anti-Semitism. And, of course, he was right. Jews are in no way associated with the diamond trade and, even if they were, like DeBeers, they would have no interest in maintaining a diamond cartel.