As is well known, normal urine contains about 2.5-3 per cent. of urea, so that graduations representing 2, 2.5, 3, and 4 per cent. are usually all that are needed, though of course many more can be easily made.

The results obtained with this apparatus have been repeatedly compared with those of more elaborate ones, and no practical difference observed.  Evidently the same apparatus, differently graduated, might be employed to determine the carbonate present in such a substance as crude soda ash or other similar mixture.  In such a case the weighed material would be put upon the mercury with water and the small tube filled with acid.

Bowdoin College Chemical Laboratory.—­F.C.  Robinson, in Amer.  Chem.  Jour.

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