392 Bibliography. 



the oxide of iron and reprecipitating this even to the eighth time. 

 Adopting this method, the precipitated oxide of iron was redis- 

 solved six times and the proportions obtained were as follows : 



Iron, 94-224 



Nickel, 6-353 



100-577 

 The sulphurets were examined also for the presence of tin, 

 cobalt, copper, lead, arsenic, &c., but without success. They 

 seemed to be only simple compounds of iron and sulphur. The 

 specific gravity of the iron was 7-5257. 



To determine more satisfactorily the presence or absence of 

 chlorine, a piece of the iron (about one pound weight) was ex- 

 posed in a humid atmosphere on a capsule under a bell glass for 

 many days, and the little drops of water which trickled down 

 and were caught by the capsule, were tested for chlorine with 

 (as before) only a very feeble indication with nitrate of silver. 

 My friend and pupil, Mr. D. Olmsted, Jr., made the analysis un- 

 der my particular direction. 



I have not had an opportunity to repeat on this specimen the 

 interesting processes described by Mr. A. A. Hayes in the last 

 number of this Journal, p. 149. 



Yale College Laboratory, Jan. 28, 1845. 



Art. XVII. — Bibliographical Notices. 



1. Report of the Commissioner of Patents for 1844 ; by the Hon. 

 H. L. Ellswokth. 8vo, pp. 520. — This report, like that which has 

 preceded it from the same distinguished source, contains a great fund 

 of information on subjects connected with AgricuUure and the Arts, and 

 their progress in our country. We quote from it the following account 

 of a new magneto- electric machine by Prof. C. G. Page. 



" In 1838, Prof. Page published in Silliman's Journal an account of 

 an improved form of Saxton's magneto-electric machine, doing away 

 with many existing objections, and furthermore rendering it at once a 

 useful instrument, by a contrivance for conducting these opposing cur- 

 rents into one channel or direction, which part of the contrivance was 

 called the unitress. The current produced in this way was capable of 

 performing the work, to a certain extent, of the power developed by the 

 galvanic battery ; and the machine was found adequate to furnishing 



