468 (C. H. Hitchcock—Helderberg Rocks in New Hampshire. 
CANE SUGAR. EQUISETUM HYEMALE. CAST IRON. 4 grams. 
0°2822 grams, -—Burned with—, -———Burned with __ 
Burned with ) Calcu- Lea Lead 
mixture. t lated. 40¢ mixt. chromate. 40% mixt. 55% mixt. chromate. 
C4312 «42°10 41°85 41°92 3°15 3°29 3°25-3°30 
H 6°55 6°43 5°92 6°01 
The cast iron was from a sample of fine borings that had been 
repeatedly analyzed with results varying between 3°25 an 
3°30. It contained both graphite and combined carbon. It 
was first treated with cupric chloride, and the carbon was col- 
lected on an asbestus filter. The analysis yielding 3°15 per 
cent was the first attempt of Mr. Hawes to estimate carbon in 
iron, and the deficiency may perhaps not be due to the small 
proportion of potassium ditincsinte (forty per cent) in the mix- 
ture. In the next analysis, the carbon was rubbed up with a 
mixture containing fifty-five per cent of dichromate ; but the 
mortar was rinsed with the forty per cent mixture. The com- 
bustions usually occupied forty-five minutes. In one case, 
aspiration, lasting fifteen minutes, sufficed to displace all oxy- 
gen from the bulbs; the flow of air (purified by streaming first 
through a soda-lime and calcium chloride tube), being resumed 
or an hour, occasioned no change in the weighed calcium 
chloride tube, nor in the joint weight of,the potash bulbs and 
their appendage. 
I behave these results justify calling the attention of chemists 
to the use of the mixture I have indicated, as a cheap, con- 
venient and efficient substitute for all the solid agents hitherto 
employed in this branch of organic analysis, cupric oxide alone 
excepted, and that only when used in conjunction with oxygen 
ga 
Art. XLIIL.—On Helderberg Rocks in New Hampshire; by 
C. H. Hircncock. 
near Lake en Share te in Canada. The crinoids were all 
small. Mr. Billings found nothing that would localize the hor 
* This Jour., III, vol. ii, p. 148. 
