J. H. Long — Polarization of Tartrate Solutions. 275 



rocks dip mostly to the east, while north of the brook the struc- 

 ture is decidedly different. A section east and west through 

 the woods shows a great synclinal of the quartzite in the argillite. 

 Following down the brook from the limestone to where the 

 woods end and then skirting the latter for a few rods north 

 to where the first wood road enters them, a little way in and 

 at the first outcrop on the south side of the road, there is a 

 well exposed coutact of the argillite beneath and the quartzite 

 above ; strike K 20° E., dip 20° W. ; the argillite flat fissile, 

 with few chloritized garnets ; the quartzite a dark gray indu- 

 rated sandstone becoming coarser higher up. The two beds 

 seem to be plainly conformable. The argillite can be followed 

 north to a point in the bluff opposite C. Frary's house with 

 uniform westerly dip beneath the quartzite, and on the west of 

 the latter the argillite is found dipping easterly beneath it, 

 though the junction is covered. I imagine this synclinal is cut 

 off on the north by a fault along the bed of Fall river, but the 

 rocks are covered here. Directly opposite the limestone across 

 the brook the quartzite contains dodecahedral garnets 10 to 

 ll mm across, bordered by chlorite. 



5. The outcrop along Fox BrooTt to the south of the 

 Williams section. — Behind the first house on the road over 

 West Mountain, after leaving the village, there is seen from 

 the road a bare bluff of blue till, and below this an outcrop in 

 the brook of Triassic sandstone ; twenty rods above, the quartz- 

 ite rests conformably upon the argillite, which contains a few 

 garnets just below the junction. It strikes !N~. 60° E. and dips 

 20° E., and the boundary is thus pushed east by the whole 

 width of the Williams section, though the fault which separates 

 them can not be exactly located. 



[To be continued.] 



Aet. XXXVI. — On the Circular Polarization of certain 

 Tartrate Solutions — III ; by J. H. Long. 



In the number of this Journal for October, 1889, 1 described 

 certain peculiarities of solutions of potassium antimony tartrate 

 when mixed with carbonates, borates, phosphates or acetates 

 in amounts insufficient to produce immediate precipitation. 

 The specific rotation of this tartrate is very high, being, (for 

 C = 5) [«] D = 1M 0, 273. No other metallic tartrate approaches 

 this rotation. It was shown in the paper referred to that the 

 addition of sodium carbonate in small amount decreased the 

 specific rotation to 55°*795, and this without precipitation of 



