* 
H. A. Newton on Shooting Stars. 193 
VI. The sixth class includes some neutral saline waters, in which the 
sulphates of lime, mhgnesia, and the alkalies predominate, chlorids 
being present only in smail quantities. These waters, like the last, 
are often impregnated with sulphuretted hydrogen, 
The above classification, although adopted originally for the 
convenient description of the mineral waters of Canada, will, it 
is thought, be found to embrace all known classes of natural 
waters, with the exception of those included under E, and some 
waters from volcanic sources holding muriatic acid. These may 
constitute two additional classes. In the first three of the classes 
above described, chlorids predominate; in the fourth, carbon- 
ates; and in the fifth and sixth, sulphates. The waters of the 
first, second, and sixth classes are neutral; those of the third 
and fourth, alkaline; and those of the fifth acid. 
he results of the chemical analysis of various waters of these 
Classes it is proposed to give in the second part of this paper. 
Arr. XXIII.— Abstract of a Memoir on Shooting Stars; by 
H. A. NEwTon, 
(Read before the National Academy of Sciences, August, 6th, 1864.)" 
. The table of altitudes of the paths of shooting stars published 
tn the last volume of this Journal, p. 185, is the basis of the com- 
: Putations, Singly, these sheirusao ate liable to large probable 
