4-28 Prof. Kane on the Powder formed by 



the smaller forms of these tissues without using a magnifying 

 power of at least 800 linear. I have had the advantage of 

 making my examination with the well-known power which 

 Mr. Bowerbank has received from Mr. Ross. 



I believe that no part of the analysis gave Mr. Rigg more 

 satisfaction than the results just alluded to. In the course of 

 his experiments, extending to some thousands, he had here- 

 tofore discovered a difference of chemical composition in dif- 

 ferent parts of the flower of the hyacinth ; but the root, which 

 he had always examined in the mass, and without separating 

 it into its two component parts, gave hydrogen and oxygen 

 in the proportion to form water. I am sure, therefore, you 

 will readily understand the pleasure which was felt in thus 

 finding, for the first time, that the chemical character of the 

 different parts of the flower were exhibited by the present 

 analysis in the different parts of the root. 



I will only add, without further observation, that I trust the 

 above remarks will convince you, that I have not " mistaken 

 cellular tissue and woody fibre for the elementary membrane 

 and fibre, the chemical analysis of which is so difficult." 

 I have the honour to be, Sir, yours, &c. 



J. B. Reade. 



LVI. On the Powder formed by the Action of Water on White 

 Precipitate. By Robert Kane, M.D., M.R.I.A., fyc. $c* 



FT is generally stated by chemical writers, that by the ac- 

 -*■ tion of much boiling water, white precipitate is decom- 

 posed completely, red oxide of mercury being left behind. 

 I never could succeed in effecting this ; but the reaction that 

 did take place appearing to me perfectly definite, and identical 

 in its results at different times, I was induced to examine it 

 in detail. 



When white precipitate is boiled in water, it is changed 

 into a heavy canary-yellow powder, subsiding rapidly, and 

 very easily dried, when it appears granular. This powder is 

 not quite insoluble in water ; when heated, it gives out am- 

 monia, azote, water, and there sublimes a mixture of calomel 

 and metallic mercury : it dissolves readily in muriatic or nitric 

 acids. Alkalies appear to have scarcely any action upon it, 

 except slightly altering its colour; when digested with iodide 



* From the Transactions of the Royal Irish Academy, vol. xvii. ; being 

 § 2 of "Researches on the Action of Ammonia on the Chlorides and Oxides 

 of Mercury." In L. and E. Phil. Mag., vol. viii. p. 495, we gave Dr. Kane's 

 " Experiments on the Action of Ammonia on the Chlorides and Oxides of 

 Mercury, and on the Composition of white Precipitate." The present 

 article concludes his observations on these mercurial compounds. 



