TRANSACTIONS OF SECTION B. 623 



Ketones react similarly. The properties of these bodies and the reaction with 

 hetonic and aldehydic bodies, as •well as with simple ketones and aldehydes, are 

 being studied. 



A further object of the investigation is the preparation of the theoretically 

 possible stereo-isomers of these imido-compounds. In addition, the therapeutic 

 value of benzylidene-diacetamide and benzylidene-dibenz amide is being studied in 

 conjunction with Dr. A. Griinbaum. 



7. A New Form of Bunsen Burner, By Hugh Marshall, D.Sc. 



The ordinary form of Bunsen burner has several drawbacks. One of these, 

 which makes itself especially felt in a large practical class, is the liability of the central 

 gas jet to become choked by matters falling down the tube : fused beads of borax, 

 &c., are particularly troublesome in this way. "Various modifications were experi- 

 mented with, in order, if possible, to obtain a form of burner which would over- 

 come this difficulty. None of these were satisfactory until the expedient was 

 adopted of abolishing the central jet altogether and introducing the gas through 

 lateral openings. Burners on this principle were found to be superior to the old 

 ones in several ways. 



The base consists of a star-shaped gun-metal tripod, with an opening and short 

 tube in the centre ; at one side of the opening, below the tube, is a small rectangu- 

 lar block. This block carries the horizontal gas supply tube. A hole of suitable 

 diameter is drilled through the block from the end of the gas tube to the central 

 tube. This serves as a jet for the introduction of the gas. Into the central tube 

 is screwed a vertical brass tube of convenient length, as in an ordinary burner. 



The new style of burner therefore differs from the old in having an inclined 

 lateral opening in place of a central gas jet ; in having the bottom of the tube 

 open right through to the bench, and in having no lateral air holes. 



It is found that the flame can be turned down very low without requiring any 

 regulation of the air supply, and, so far as that is concerned, an ah" regulator is 

 almost superfluous. In order to obtain a luminous flame, however, a regulator is 

 fitted on the under side of the base. It consists simply of a pivoted diaphragm of 

 sheet brass, with an arm projecting beyond the base to admit of easy manipulation. 



Further improvements are contemplated with regard to this part of the 

 mechanism, however. 



A considerable number of burners have been made on this plan, and have been 

 in use for several months. They work very satisfactorily. 



WEDNESDAY, AUGUST 25. 



The following Papers and Reports were read : — 



1 . Molecular Movement in Metals. 

 By Professor W. C. Roberts-Austen, C.B., F.R.S. 



2. The causes of Loss incurred in roasting Gold Ores containing Tellurium 



By Dr. T. K. Rose. 



It is a common experience that when ores containing tellurium are roasted 

 considerable losses of gold occur. It has been generally believed that the losses 

 are due to volatilisation, although little direct evidence of this has been brought 

 forward. 



In the paper experiments are described which point to a diSerent conclusion. 

 Samples of an alloy of gold and tellurium, containbg 78-0 per cent, of the former 



