Some Analysis of the Urine of Reptiles.

herald the rain at B. Here the pointer, at S, actually gave up in despair and rested for a while on the stops; but it soon got free again and has not succumbed since, etc. The lag condition inside of the room as compared with those outside were well marked. At mid-day there is usually a slight rise of the pointer, owing to increased temperature and dryness. So far as I can see there is no reason why such an apparatus should not be quite trustworthy. Without using mirrors, it could easily be made twenty times more sensitive. The gelatine film attached has been in the laboratory for at least twenty-five years under the same atmospheric conditions. The question is therefore pertinent whether we know as much about the continuity of thermodynamic equilibrium, or about colloids, as this simple instrument might answer. C. BARUS BROWN UNIVERSITY, PROVIDENCE, R. I.