220 



Mr. A. Matthiessen on the Expansion by [June 21, 



•4528 of salt gave 1-3155 Ag CI ; .-. 59*94 per cent. CI. 

 Chloride of ammonium would give 6G'33 



Chloride of ethylamine 43*55 „ 



From these numbers it appears that ammonia is capable of partially ex- 

 pelling ethylamine from its compounds, and thus we have an explanation 

 of the apparent anomaly of the appearance of ammonia with the ethylamine 

 in the above-described experiments. It appears therefore that pure ethyl- 

 amine may be readily obtained in the following manner. Equal volumes 

 of iodide of ethyl, strong alcohol and ammonia are to be digested together 

 for about half an hour, at a temperature somewhat below that of boiling 

 water, with continual shaking ; the product of this operation boiled to 

 expel excess of ammonia, and then distilled from potash — the distillate 

 being received into dilute sulphuric acid, the ammonia separated by means 

 of alcohol, and the alcoholic solution of the mixed sulphates treated with 

 sufficient potash to liberate about of the bases present. On distilling 

 this mixture, pure ethylamine, accompanied with alcohol and water, are 

 the sole products found in the distillate. 



IV. " On the Expansion by Heat of Metals and Alloys." 

 By A. Matthiessen, F.R.S. Received June 14, 1866. 

 (Abstract.) 



In a paper "On the Expansion by Heat of Water and Mercury'**, a 

 method of determining the expansion of bodies is described, by which 

 good results can be obtained with comparatively small quantities of the 

 substances to be experimented with. This method, that of weighing the 

 body in water at different temperatures, has been employed for the present 

 research. The results obtained are given in the following Tables : — 



Table I. — Formulae for the Correction of the Cubical Expansion by Heat 



of the Metals. 



Cadmium V,= V„ (1 + 10"^ x 0-8078^+ IQ-' x O'UOf) f. 



Zinc V,=V„ (1 + 10--^ X 0-8222^+10-^ x 0-0706^^). 



Lead V,= (I + IO"* x 0-8177^+10-^ x 0-0222^^). 



Tin V,=V„(l + 10-*x0-6100^+10-^x0-0789i^). 



Silver V,=V,(l + 10-^x0-5426i+10-^x0-0405^^). 



Copper V, = V, (1 + 10-^ x 0-4463^+10-^ x 0-0555^^). 



Gold V,=Vo (1 + 10-^ X 0-4075^+10-^ x 0-0336f ). 



Bismuth V,=Vo(l + 10-*x 0-3502^ + 10-^ xO-0446f2). 



Palladium V,= (1 + 10"^ x 0-3032^ + 10-' x 0-0280^"). 



Antimony V,= V„ (1 + 10"^ x 0-2770^ + 10"' X 0-0397O. 



Platinum V.^V^ (1 + 10"^ X 0-2554^+ 10"' X 0-0104^"). 



* Phil. Trans. 1866, part 1. 



t I have employed this method of ^A'riting the formulte to prevent mistakes in the 



