Chemistry and Physics. . 7 
difficulty ; on heating there is a slow evolution of gas, and a chlorid is 
formed which appears to be richer in tin than the original radical. This 
ehlorid crystallizes with difficulty and has an oily consistency at ordinary 
temperatures, it has a str rong and penetrating smell, and on heating gives 
off a vapor which is very irritating to the skin. A ‘corresponding bromid 
rye exists, but the other salts are not yet described. 
the Compounds of Organic Radicals with the Metals of the 
wibeke —Ha.iwacus and Scuararik have studied the action of iodid of 
tals. 
ethyl upon several of the earthy meta en magnesium is heated in 
a closed tube with the iodid, the metal is gradually converted into a 
white mass. On opening the tu be gas is Rate off, and e white mass 
ee of hydro-carbons with traces of ethy ene Finely divi- 
: en ie 
authors Propose to to exte nd their investigation to other metals. Ww. G. 
araday’s peer hes in Chemistry and Physics—(Researches in 
Chemistry wid Physics, by Micnagt Farapay, D.CS., F.BS., &e., &c.). 
ie Richard Taylor and William Francis, Printers and Publishe 
to the University of London, 1859. 496 pp. 8vo, with 3 plates—The 
illustrious freon of this volume says in ve preface, “The reasons whic 
induce me to gather together in this volume the various physical and 
dheaiival. shoe scattered in the Philosophical Transactions and else- 
‘ where, are the same as those which caused the Experimental Researches 
in _ Electricity to be collected into one series.” Every student of these 
sciences will acknow ror hi a debt of gratitude to Englan nd’s most Fp: 4 
ee t this paper at full length. Jt was at at the beginning of my communications 
- the public, and i its results very important to me. oe ate 
me the analyses to make, as a first attempt in chemistry, at a time when my fear 
Was greater than my confidence an) psitn nt at a time 
also when I had no fg thought of ever wrillii? ki per tnesatss hago The ad- 
sition of his own comment and the publication of the paper encouraged me to go 
; ing fi ne of Pp 
in this volume. Their trans ‘tight : ’ into other — In- 
my boldness; and now that forty years have elapsed and [ can look back 
i icati ve 0, 
acter has changed, that I haye not, either now or forty years ago, 
