Martin's excitement cooled. It seemed to him that she clung too closely to her partners, that she followed their steps too eagerly. (7.3.15)
When Martin first takes Leora to a frat dance, his biggest concern is that no one will want to dance with her. But on the contrary, a bunch of guys want to dance with her, and before he knows it, Martin finds himself scowling with jealousy while Leora has a good time.
"I wasn't jealous—Yes, I was. Oh, I can't help it! I love you so much. I'd be one fine lover, now wouldn't I, if I never got jealous!" (7.3.19)
Martin tries to deny that he was jealous of Leora dancing with other guys, but he doesn't defend himself for long. He knows full well how jealous he was and he wishes he wasn't. But that's how our emotions work sometimes, especially when our pride is on the line. We don't always have a choice over what we feel… especially in matters of the heart.
"Well, if you want to know, Martin Arrowsmith, I'll have no more of these high jinks with that Orchid girl!" (19.4.39)
It's Leora's turn to be jealous when she notices Martin getting a little too chummy with a teenage girl named Orchid. She's not going to stomp around and kick Martin out of the house, but she's definitely going to tell him to knock it off. One of the things that Martin loves about Leora is that she clings to him so jealously.
"I'm a cavewoman, and you'd better learn it, and as for that Orchid, with her simper and her stroking your arm and her great big absurd feet--- Orchid!" (19.4.39)
Leora seems calm at first, but she can't help but sneak in a few insults about Orchid Pickerbaugh, who's been flirting with Martin. All in all, Leora is more than reasonable about the whole flirting thing. But underneath all her reasonable exterior, she's a woman who's ready to kill to have Martin all to herself.
And Leora made no comments, though for a day or two there was about her a chill air which the busy Martin did not investigate. (20.4.13)
When Martin and Leora go on a weekend getaway to the Pickarbaughs' cottage, Martin spends a little too much time playing in the snow and wrestling with Orchid. Leora notices this and acts chilly to Martin the next few days. But Martin knows enough to stay away from the topic and to consider Leora's coldness a warning.
To Gustaf Sondelius, dukes and cobblers were alike remarkable, and Martin was sometimes jealous when he saw Sondelius turning to a cocoa-broker's clerk with the same smile he gave to Martin. (33.6.20)
Martin considers Sondelius a mentor, and for that reason, he doesn't like it when he sees Sondelius giving "normal" people the same smile he gives to Martin. Martin wants to think that he's special in Sondelius' eyes, and he gets jealous whenever he sees evidence that he isn't.
Constant criticism was good, if only it was not spiteful, jealous, petty— (36.3.3)
Martin cringes a little whenever someone criticizes him or his work. But deep down, he knows that criticism can make him better, as long as it's not motivated by petty feelings like spite or jealousy.
"You see, I've come to stay! I'll build a house near here; perhaps right across the lake." (40.3.15)
Martin's second wife Joyce is a lot different from his first wife, Leora. While Leora was always jealous of other women and never of Martin's work, Joyce is jealous of Martin's work and not of other women. Joyce hates that Martin loves his work so much more than her and their son John. That's why she decides to build a big ol' house next to Martin's private lab in Vermont—so she can always be near. The problem is that Martin goes to Vermont specifically to get away from her.
But now Arrowsmith, once the poorest of them all, came by limousine with a chauffeur who touched his hat, and Holabird's coffee was salted. (38.1.1)
Dr. Holabird enjoys being married to a rich woman because he gets to drive in a private car to work while all his colleagues take the train. Martin rains on his parade, though, by marrying an even richer woman and getting his own chauffeur.
There was a simplicity in Martin, but it cannot be said that he did not lick his lips when Holabird mooned at the chauffeur. (38.1.2)
Martin knows full well that Dr. Holabird is jealous of his luxurious car and the chauffeur that drives him to work. And even though Martin tries to be above this kind of pettiness, he can't help but revel in Holabird's jealousy.