Bell's meth'od

[William Blair Bell, Liverpool physician, contemporary.] For estimating the amount of calcium (not bound up with protein) in the blood; 100 c.mm. of blood is mixed with 250 c.mm. of a 1—30 aqueous solution of oxalic acid; after standing for 10 minutes, 250 c.mm. of glycerin, 5 parts, in 95 parts of a i per cent, solution of acetic acid is added; 100 c.mm. of the mixture is then added to 500 c.mm. of distilled water, and of this one drop is placed in a Thoma counting chamber and the crystals of calcium oxalate are counted. The relative number of crystals as compared with those in a 1-6000 solution of calcium oxide in distilled water constitutes the calcium index.