642 REPORT — 1887. 



was pointed out that our investigations in regard to tlie cotton fibre must embrace 

 its meclianical and chemical structure. 



After speaking briefly of the mechanical structure it was shown that cotton in 

 common with all vegetable substances has for its base cellulose. This substance 

 was formerly supposed, so far as cotton is concerned, to be a definite and fixed 

 compound having the composition indicated by the formula C^HjoO-. The results of 

 the analysis of various kinds of cotton were then referred to, and it was shown that 

 there is strong reason to suppose that the fibre as met with under ordinary circum- 

 stances is really composed of a series of bodies more or less corresponding to this 

 formula but differing from it in regard to the arrangement of the hydrogen and 

 oxygen atoms within the molecule and thus constituting a series of celluloses 

 which have a distinct differentiation rather than one single composition. It was also 

 noticed that, having due regard to the atomicity of the constituents of the typical 

 cellulose molecule it is impossible to conceive that the hydrogen and oxygen atoms 

 are arranged in the molecule, in the same atomic combination as water, although 

 water is always associated with the fibre to the extent of 5 to 7 per cent, and 

 hence the conclusion is drawn that this water of hydration is not an essential con- 

 stituent of the cellulose molecule. After summing up our knowledge of the 

 general chemical characters of the cotton cellulose reference was made to the hydra- 

 tion and de-hydration changes of which cellulose is capable as exhibited in recent 

 researches on this subject, and special mention was made of oxycellulose and its 

 reactions. The behaviour of this body and its allies as distinguished from cellulose 

 and the reactions of the latter when treated with acids and alkalis were then dis- 

 cussed, and the light which these throw on the probable constitution of cotton 

 was pointed out. 



Considerable stress was then laid upon the fact that the cotton fibre always con- 

 tains mineral matter to the extent of 1 per cent, as an integral part of its structure, 

 and the importance of this as a factor in the chemical reactions of the cotton fibre 

 was insisted upon, and various researches which throw evidence upon this point were 

 mentioned. Finalh', notice was taken of the invaluable presence of oils, fats, and 

 waxes along with cotton fibre, and the necessity for due consideration of this fact 

 in the methods employed in manipulating the fibre for technical purposes. 



Sub-Section B.— organic CHEMISTRY. 



1. Second Report of the Committee for investigafinri Ziomeric Naphthalene 

 Derivatives. — See Reports, p. 231. 



2. Isomeric Change in the Phenol Series. Bg A. R. Ling. 



3. The Cotistitntion and Relationship of the Eurhodine and Saffranine 

 Classes of Colouring Matters, and. their Connection ivith other Oroups of 

 Organic Compounds. By Dr. 0. N. "Witt. 



4. On the Constitution of Azimido-Compounds. 

 Bij Drs. NoELTixG and Abt. 

 The azimido-compounds discovered by Hofmann, Ladenburg, and Griess, when 

 actino- with nitrous acid on ortho-diamines, have, accordino- to Griess's opinion, the 



constitution represented by the following formula, R" | /NH, for example, the 



derivative of ortho-phenylene-diamine would be OgHj | /NH. K6kul6 proposed an- 

 other formula, diflfering from the preceding one by the manner in which the nitrogen 



