Collishaw went up to speak to his wife before going out.

And then Ransford asked Mrs.Batts for something--I forget what--some small matter which the Collishaw's hadn't got and she had, and she went next door to fetch it.
Therefore--do you see ?--Ransford was left alone with--Collishaw's tin bottle!" Bryce, who had been listening attentively, looked steadily at the inspector.
"You're suspecting Ransford already!" he said.
Mitchington shook his head.
"What's it look like ?" he answered, almost appealingly.

"I put it to you, now!--what does it look like?
Here's this man been poisoned without a doubt--I'm certain of it.

And--there were those rumours--it's idle to deny that they centred in Ransford.

And--this morning Ransford had the chance!" "That's arguing that Ransford purposely carried a dose of poison to put into Collishaw's tin bottle!" said Bryce half-sneeringly.