118 Prof. M. Simpson. Chemical Notes. [Feb. 21, 



different degrees of hardness, at any rate, for the temperatures em- 

 ployed, magnetisation evidently produces the same kind of effect as 

 with the soft iron. The amount of the alteration in the case of soft 

 iron must have reached at least as high as 10 per cent., and may be 

 greater. The experiments which the writer has made on electrical 

 conductivity have shown that this is also very appreciably altered 

 by magnetism, at least 6 per cent., even when the magnetisation 

 was evidently not complete (Proc. of R. S., June 17, 1875), and has 

 some reasons for believing that the amount of alteration for thermal 

 and electrical conductivity will be found to be not very different. He 

 hopes, however, to thoroughly investigate the whole subject. 



It should be mentioned here that Sir "William Thomson (Phil. 

 Trans., Feb. 28, 1856,) expresses a strong opinion that the experiments 

 of Dr. Maggi on this subject, on which he says doubts have been 

 thrown by others, would be found correct, basing his opinion on the 

 results of his own experiments on the alteration of electrical con- 

 ductivity by magnetism. And, though the writer had some years ago 

 made some attempts in the present direction (unfortunately before 

 perusing Sir William Thomson's exceedingly valuable paper), he 

 cannot conclude without expressing how greatly the suggestions there 

 thrown out have assisted him in these and other experiments. 



II. " Chemical Notes." By Dr. Maxwell Simpson, F.R.S., Pro- 

 fessor of Chemistry in Queen's College, Cork. Received 

 January 2, 1878. 



On the Direct Formation of the Chloro-Bromides of the Olefines and other 

 non-saturated Compounds. 



Chloro-bromide of Ethylene (C 2 H 4 ClBr). 



The first step towards the direct formation of this and other chloro- 

 bromides is, of course, the preparation of the solution of chloride of 

 bromine. This I endeavoured to prepare by a process analogous to 

 that by which I had formed the chloride of iodine.* I found, however, 

 that in passing the chlorine into the bromine and water, a larger 

 quantity of the former is carried off in the form of vapuar. I con- 

 tinued the passage of the gas, nevertheless, till all the bromine was 

 dissolved and the solution assumed a faint yellow tint. On conducting 

 defiant gas into this, I obtained a very small quantity of an oily liquid, 

 part of which boiled between 106° and 110° Cent. Altogether, it is by 



* " Annalen der Chemie," cxxxyi, 141. 



