On Wednesday 23 January 2008, Dan Asimov wrote: [quoting the NYT]
Half the doctors were given a glass bottle of epinephrine labeled “1 milligram in 1 milliliter solution.” The other half had bottles labeled “1 milliliter of a 1:1000 solution” — exactly the same thing but expressed as a ratio instead of a concentration. In either case, the correct dosage would be 0.12 milliliters of the solution.
[himself]
Can someone please help me understand why the two solutions described should have the same concentration of epinephrine? I honestly don't get it.
Presumably x:y means x kg per y litres of solution, which (for small x/y) is more or less equivalent to x kg per y kg of solution and is therefore a reasonable thing for x:y to mean. In that case, 1:1000 is 1g/l, or 1mg/ml. Which is the same as the first bottle. -- g