TRANSACTIONS OF THE SECTIONS. 21 



cannons, each alternately to be in process of being charged while the other was 

 at work. This, however, either at Greenwich or Edinburgh could be readily 

 accomplished. 



On the Cohesion-Figures of Liquids. By C. Tojilinson, F. C.S, 



This subject was introduced to the British Association at Manchester, in 1861. 

 The author now stated the progress which had been made since that time, and 

 introduced two new sets of figures. The principle of the examination by this me- 

 thod is to place a drop of a liquid on the surface of clean water in a chemically 

 clean glass, when a figure is produced which was characteristic of the liquid so 

 tested, and capable of being used for its identification. The figure fonned is a func- 

 tion of cohesion, adhesion, and difliisibility. If any one of these forces be varied, 

 the figure varies. The figures of alcohol, for example, on water, mercury, the fixed 

 oils, melted lard, spennaceti, paraffin, sulphur, &c., are all different. A new set of 

 figures is produced by allowing the drop to subside in a column of liquid instead of 

 diffusing over its surface. These last the author calls " submersion figures of 

 liquids." The figm-e of a drop of oil of lavender in a column of alcohol thus pro- 

 duced is singularly complicated and beautiful. A drop of oil of cloves or of cin- 

 namon in a column of castor oil also forms a remarkable submersion figure. The 

 test by cohesion-figures was stated by the author to be so delicate as to readily 

 distinguish difl[^erences between oils so closely related as the oleines of beef-fat and 

 mutton-fat. 



CHEMISTET. 



Address by William Odling, M.B., F.R.S., F.R.C.P., Secretary to the Che' 



mical Society, Lecturer on Chemistry at St. Bartholomew's Hospital. 

 At the Leeds Meeting of the British Association in 1858, Sir John Herschel, the 

 then President of the Chemical Section, opened its proceedings with an introductoiy 

 address of singular interest, and thereby established a precedent which, with a 

 solitary exception, has been uniformly adopted by successive occupants of the posi- 

 tion which I have now the honour to hold. Following in his footsteps, Imu/o inter- 

 vallo, I in my turn now venture upon a few words of introduction to the proper 

 business that we have in hand. In the first place, I may congi'atulate the Section 

 upon the presence among us of so many distinguished chemists, including several 

 of my more immediate predecessors. I need scarcely express the personal gratifi- 

 cation I feel at meeting them here, nor say how much their presence relieves me 

 from the feeling of responsibility and self-mistrust with which I undertook the 

 honourable office so kindly entrusted to me by the General Committee, feeling now 

 that, upon any occasion of difficulty, I shall have them to apply to for counsel 

 and assistance. 



After the great diversity, or rather antagonism, of opinion which has existed for 

 the last dozen years or so,'l am almost bound to take a somewhat prominent notice 

 of the substantial agreement which now prevails among English chemists as to the 

 combining proportions of the elementary Dodies and the molecular weights of their 

 most important compounds. The present unanimity of opinion on this fundamental 

 subject among those who have given it their attention is, I conceive, greater than 

 has ever been the case since Dalton published his ' New System of Chemical Phi- 

 losophy,' more than half a centurj' ago. As yet, indeed, the unanimity of practice 

 falls considerably short of the unanimity of belief ; but, even in this du-ection. great 

 progress is being made, to which the publication of Miller's 'Elements of Che- 

 mistry,' Watts's ' Dictionary of Chemistry,' and Hofmann's ' Jury Report on the 

 Chemical Products in the Great Exhibition,' will doubtless give a yet stronger im- 

 petus. As was well observed by Dr. Miller at a previous Meeting of this Association, 

 " Chemistry is not merely a science ; it is also an art, which has introduced its 

 nomenclature and its notation into our manufactories, and in some measure even 



