321 
of Edinburgh , Session 1876-77. 
and oxygen is further oxidised, with separation of yellow sulphur, 
yielding (2) hyposulphite of trimethyl-sulphine. 
The action is thus similar to that of sulphuretted hydrogen on 
potash or carbonate of potash, but takes place with much greater 
rapidity. 
The examination of the sulphide and polysulphide of trimethyl- 
sulphine will form the subject of the next part of the paper. 
2. On Links. By Professor Tait. 
(Abstract.) 
Though in my former papers on knots I have made but little 
allusion to cases in which two or more closed curves are linked 
together, the method I have employed is easily and directly ap- 
plicable to them. I stated to the British Association that the 
number of intersections passed through in going continuously 
along a curve, from any intersection to the same again, is always 
even — whether it be linked with other curves or not Hence, even 
when a number of closed curves are linked together, the intersec- 
tions may be so arranged as to be alternately over and under along 
each of the curves. 
When this is done, each of the meshes has all its angles right or 
left handed ; so that Listing’s type-symbols may be employed, just 
as for a single knotted curve. The scheme, however, consists of 
as many parts as there are intersecting curves — each part contain- 
ing, along with each of its own crossings twice, each of its intersec- 
tions with other curves once. 
represents a couple of ovals linked together. 
When three ovals are joined, so as to form an endless chain, we 
have 
Thus 
AB | A AB | A 
or 
2r 2 
2P 
A B C D | A DCEFjD FEBA | F 
or 
