296 J.C. Waison—Discovery of a new planet. 
the “clay” thus obtained being, of course, more or less con- 
taminated with some of the finest silt; which is precipitated 
with it by salt, provided the relative amount of clay is not too 
small. Otherwise a slight turbidity may remain for several 
days in the decanted liquid, which cannot then be cleared by 
the further addition of walk 
50°%™ of a saturated brine (i. e., 1-5 per cent of salt) is ordinarily 
sufficient to precipitate one liter of clay water; the precipita- 
tion is much favored by warming. Half the quantity, or even 
less, will do the same, but more time is required, and the pre- 
cipitate is more voluminous. 
As it cannot ordinarily be washed with pure water, it must 
be collected on a weighed filter, washed with weak brine, dried 
at 100° and weighed, It is then again placed in a funnel and 
washed with a weak solution of sal ammoniac, until all the 
chloride of sodium is removed. The filtrate is evaporated, the 
residue ignited and weighed : its weight, plus that of the filter, 
deducted from the total weight, gives that of the clay itself. 
In € cases, especially of clays and subsoils deeply tinged 
with iron, the clay, after dr ing at 100°, will not readily diffuse 
in water, and can be wehed with pure water until free from 
salt ; it can then of course be weighed directly. 
[To be continued.] 
siren 
ArT. XXXIL—Discovery of a new Planet, and observations on 
that discovered June 18th; by JamEs C. WarTSON. 
_ON the 29th of July I discovered a planet of the 12th mag- 
nitude and observed the following place : 
Ann Arbor M, T. @ é ; 
1873 July 29 142 1™ Qs 23h gm 19°535 men? SHAT 
Ann Arbor M. T. a é 
1873 August 16 19% 39m 4s 935 2 41:50 wen? 37'5 92 
3 14 24 23 2 40°23 2 38 9S 
16. 200 as 4 23 2 38%5 2 38 92 
16 14\59 27 23 2 37°35 2 38 12°8 
17 10 i296 23 Qo 208 2 39 36°7 
17 10 46 20 23 2 1°98 Q 39 471 
9311.45 7 22 57 28°37 2 52 51°3 
3 — 
_ By means of these observations I computed the following 
circular elements : 
