448 New Tables for finding the Deviation of a Star 



The chlorine and carbonic oxitle are, it is evident fronS 

 these last facts, united by strong attractions ; and as the pro- 

 perties of the substance as a peculiar compound are well 

 characterized, it will be necessary to designate it by some 

 simple name, I venture to propose tharof phosgene, or 

 phosgene gas ; from tiw;, light, and yivot/.a.t, to produce, 

 which signifies formed by light ; and as yet no oibcrmode 

 of producing it has been discovered. 



1 have exposed mixtures consisting of different propor- 

 tions of chlorine and carbonic acid to light j but have ob- 

 tained no new compound. 



The proportions in which bodies con>bine appear to be 

 determined by fixed laws, which are exemplified in a variety 

 of instances, and particularly ii\ the present compaund. 

 Oxygen combines with twice its volume of hydrogen and 

 twice its voluuie of carbonic oxide to form water and car- 

 bonic acid, and with half its volume of chlorine to form 

 euchlorine; and chlorine reciprocally requires its own vo- 

 lume of hydrogen and its own volume of carbonic oxide 

 to form muriatic acid and the new gas. 



This rel.Htion of proportions is one of the most beautiful 

 parts of chemical philosophy, arnl that which promises fair- 

 est, when prosecuted, to raise chemistry to the state and 

 certainly of a mathematical science. 



LXIX. New Tables for finding the Deviation of a Star in 

 North Polar Distance and Right Ascension. By Mr. T. 

 FiRMiNGER, late Assistant Astronomer at the Royal 

 Observatory, Greenwich*. 



In the present improved state of astronomy, every means 

 which tends to simplify calculation rs readily embraced by 

 the practical astronomer. With this view a variety of tables 

 at different times have been published, and some of them 

 so concise and simple that they seem to afford but little if 

 any rov)m for further improvement ; whilst others, however, 

 have not yet been so far improved, but that they still admit 

 of a considerable degree of slmpllficalion ; and of these the 

 means of deiern)ining the nutation of a star in north polar 

 distance from tallies as heitherto published, is an instance. 



Finding a considerable inconvenience in the computa- 

 tion of this equation of constant use in the reduction of 

 meridional zenith distances from Dr. Maskelyne's Tables, 



* Master of an Academy for the Instruction of a limited Number of 

 Younij Gentlemen in the Theory and Practice of the Mathematics and Ma- 

 thematical Sciences. 



published 



