146 G. H. Stone — Drift Scratches in Jfaine. 



Experiments 1 and 2 were parts of the same experiment 

 which was interrupted to see if the loss of weight were propor- 

 tional to the amounts of air in the line marked " excess leav- 

 ing." In all three experiments, 1163 liters more passed out 

 than entered the apparatus, the sum of the losses in weight is 

 2*8 miligrams. The amount of sulphur trioxide which escaped 

 may be computed at 4 milligram. The remaining 24 milli- 

 grams is the weight of aqueous vapor carried out of the ap- 

 paratus by 1163 liters of air. The quantity subtracted is 

 affected with some uncertainty, since the air used in the experi- 

 ment on the evaporation of sulphur trioxide was not purified 

 from organic matter, and there may have been reduction of the 

 acid to the dioxide, and reoxidation to sulphuric acid. But 

 with the approximation so far obtained, the water which strong 

 sulphuric acid fails to remove from a slow current of air is 

 about the four hundred and fiftieth or five hundredth part of a 

 milligram in a liter of air. 



Dibbits* showed that 308 liters of air dried by sulphuric acid 

 gave up •'! milligram to phosphorus pentoxide. It is curious 

 that this is the quantity which my experiments show to be left 

 by sulphuric acid in that quantity of air. The obvious in- 

 ference may be true, but is not safe. I shall hope to repeat 

 these experiments on the evaporation of sulphur trioxide from 

 sulphuric acid with purified air, and those on residual moisture 

 left in a gas by the acid with some form of apparatus permitting 

 more accurate weighing than Liebig's bulbs. 



749 Republic Street, Cleveland, Ohio, May 25th, 1885. 



Art. XXII. — Local Deflections of the Drift Scratches in Maine ; 

 by Gr. H. Stone. 



On almost every glaciated surface in Maine may be found 

 isolated drift scratches aberrant both in direction and outline. 

 Often these are somewhat curved and may grow deeper toward 

 their south ends where they usually terminate abruptly. In a 

 few cases I have found reversed curves making the scratch 

 resemble the mathematical sign of integration. They some- 

 times vary 10° or even 20° from the average direction of the 

 glaciation and hence they often intersect other scratches near 

 them. Indeed it is the exception to find the glacial scratches 

 exactly parallel even when adjacent, and it is often by no 

 means an easy task to decide which of a given series of 

 scratches most nearly represents the true direction of the gla- 

 cial movement at that point. The writer is persuaded that the 

 time has come for glacialists to unite in adopting some more 



* Zeitschr. Anal. Chem., vol. xv, p. 160. 



