

Chemistry and Physics. 265 



L 0-1674 grms. silver-salt gave 0*0535 grm. silver. 



II. 0-1715 " " u 0055 " « . 



III. 0-161 " " M by combination 0-310 grm. carbonic 

 acid and 0-126 grm. of water. 



IV. 0*1845 grm. silver-salt gave 0*3561 grm. carbonic acid and 0*1445 

 grm. water. 



According to these values, the following formula is calculated for 

 the silver-salt : 



C 60 H 57 O 3 +2AgO. 



Calculated. Found. 



_A 



x 



land in. ii and iv. 



60 C 360 5348 5251 5262 



57 H 57 8-47 8 69 5870 



3 24 4-58 4-47 4-16 



2AgO 232 34-47 3433 3452 



C 60 H 57 O 3 +2Ag 0=673 10000 10000 10000 



The slight loss in carbon will be easily accounted for, when the small 

 quantity of substance which I was enabled to submit to analysis is 

 taken in consideration. 



Margaritinate of Barytes. — Notwithstanding all the pains I took, I 

 did not succeed in obtaining this salt of a constant composition. The 

 precipitates partly obtained by decomposition of a watery solution of 

 the soap with chlorid of barytes, partly by precipitating the alcoholic 

 solution of the potash salt in the same way, formed a white, curdy, vo- 

 luminous mass, soluble in alcohol and ether, insoluble in water, and 

 which was not altered by exposure to a temperature of 100° C. 



Margaritinic ether was easily produced by introducing a stream of 

 hydrochloric acid gas into an alcoholic solution of the acid in question ; 

 the ether separated at the surface of the liquid in yellow oily drops, 

 becoming crystalline in cooling. After having washed them repeatedly 

 with water, they had a melting point of 32° C. The quantity obtained 

 was loo small to allow of an organic analysis. 



2. On some New Phenomena of Light and Actinism ; by Mr. Hunt, 

 (Proc. Roy. Soc, Atheu., No. 1122.)— The chemical change produced 

 in chlorid of silver when exposed to the action of the sun's rays, by 

 which powerful chemical affinity is broken up, chlorine liberated and 

 silver in a state of fine division left, was selected as an exemplification 

 of the actinic force, which was the subject of consideration. This 

 chemical change takes place in white light, and hence all those photo- 

 graphic phenomena which have created so much interest have been 

 referred to luminous power. If, however, we examine the conditions 

 °f light as analyzed by the prism,— presenting not seven colored bands 

 as stated by Sir Isaac Newton, but nine as proved by recent experiments, 



it is found that these colored bands possess opposite properties. For 

 instance, the chlorid of silver will not darken in the mean luminous ray 

 of the spectrum, nor will it darken either at the end which gives the 

 greatest calorific effect, or at the end which is embraced by the laven- 

 der ray, usually regarded as representing the most chemically active 

 Part; consequently we find three points in the spectrum which will not 



Second Seeies, Vol. VIII, No. 28.— Sept., 1849. 34 



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