What is a "dream bomb" in Agatha Christie's "Third Girl"?

Question

In Third Girl (1966) by Agatha Christie, the character Dr Stillingfleet describes the condition of his patient:

“She’s down at Kenway Court. Came like a lamb. Can’t tell you much yet. The girl’s full of drugs. I’d say she’d been taking purple hearts, and dream bombs, and probably L.S.D.… She’s been all hopped up for some time. She says no, but I wouldn’t trust much to what she says.”

What is a “dream bomb”? I would have guessed that it was an invention, except that “purple heart” really was 1960s drugs slang:

purple heart, n. 3. British colloquial. Originally: a tablet of the drug Drinamyl, containing dextroamphetamine and amylobarbitone (in reference to its colour and shape). Later also: a tablet of any amphetamine.

_{Oxford English Dictionary}

Answer 1

The plot hinges on the dream state induced in Norma by drugs administered by Robert Orwell, posing as her father, and his wife.

I believe that Christie introduces the notion of there being lots of 'new' drugs around, possibly as an authorial defense against people picking holes in the storyline if some real named drug such as LSD or Purple hearts wouldn't have quite the effect required by the narrative, but also as a means of dropping breadcrumbs for the reader that 'dreams' and 'drugs' are linked and important.

At one point in the story, Claudia and Frances are in discussion, about Norma, David, the drug and party scene etc:

"I was up too late last night," she said.

"At Basil's party. I feel dreadful. Oh well, I suppose black coffee will be helpful. Have some more before I've drunk it all? Basil would make us try some new pills — Emerald Dreams. I don't think it's really worth trying all these silly things."

So with the Op's question about 'Dream Bombs' and the 'Emerald dreams' Frances sampled we have two drugs introducing the notion of an induced dream state.

So, having searched online and using Google books and found nothing to link either name to drugs, I think it safe to say that neither of the 'dream drugs' map to contemporaneous street pharmaceuticals but are there as signposts to the reader.