417 
A speculation of the Singalese is mentioned relative to the white 
races, viz., that they are the descendants of Albinos, and, ab origine, 
merely an accidental variety. 
The author seems to think that analogy is not unfavourable to this 
hypothesis, keeping in mind how great is the variety of colour, and 
its gradations from light to dark, amongst Europeans, and, in the 
instance of our domesticated animals, how colour is hereditary ; and 
also on the ground that the sun’s rays have a greater darkening 
effect on persons of brown skin than on those of fair ; and that the 
former, especially the darkest — the blacks — are better able to resist 
malaria and the effects of tropical climates than the whites, and 
have thereby a better chance of escaping disease, and a'premature 
death and extinction of race. 
3. Note on the Bisulphide of Iodine. By Frederick Guthrie. 
An examination of the action of certain compound halogens 
towards some of the olefines (the results of which I hope shortly to 
lay before this Society), has led me to consider incidentally the pre- 
paration of some of the compound halogens in the pure state. 
Of compound halogens, while the constitution of none is more 
invariable and definite than that of the bisulphide of chlorine, the 
bisulphide of iodine can scarcely be said to have been prepared, de- 
spite the so strong analogy between chlorine and iodine. 
That iodine combines with sulphur is well known ; that such 
combination is attended by the liberation of heat, is equally well 
established. And since homogeneous mixtures of the two may be 
prepared in all proportions, it is clear that a substance having the 
percentage composition of the bisulphide of iodine may be formed. 
Bodies so formed have little or no title to the name of chemical 
compounds. 
If we remember, on the one hand, the fact which I have abun- 
dantly proved elsewhere, that an equivalent of bisulphide of chlorine 
functions as two equivalents of chlorine, or, as some chemists would 
express it, that the molecule of bisulphide of chlorine is biatomie ; 
and if we further remember, that at least two equivalents of chlo- 
rine or of zinc are required to recompose iodide of ethyl according 
to the equations — 
