ON THE CARBOHYDRATES OF CEREAL STRAWS. 265 
This concludes our report of progress. We trust to have given satis- 
factory evidence of useful work, and of having taken advantage of the 
opportunities provided by the Association in their grant of funds. 
Lioneric Naphthalene Derivatives.—Tenth Report of the Committee, 
consisting of Professor W. A. TrLDEN and Professor H. EH. ARM- 
STRONG. (Drawn up by Professor ARMSTRONG.) 
THE completion of the investigation of the fourteen possible trichloro- 
naphthalenes (including the proof that there are only fourteen) by Dr. 
Wynne and the writer (referred to in the last report), following that of 
the ten possible dichloronaphthalenes, marks the termination of a section 
of our work.—perhaps of greater importance than any other, establishing, 
as it dues, two complete series of reference compounds by means of which 
all other di- and tri-derivatives of naphthalene may be classified ; whilst, 
at the same time, it affords unquestionable confirmation of the accuracy of 
the train of argument on which our present views of the constitution 
of benzenoid compounds are based, and places the symmetrical structure of 
naphthalene beyond all doubt. 
Although great progress has been made in collecting the material 
needed for the discussion of the laws which govern substitution in the 
naphthalene series in the case of derivatives containing either halogens, 
or nitro or other oxylic groups, or amidogen, or hydroxyl, before entering 
on the final consideration of the results, it is essential to obtain further 
evidence as to the manner in which the interactions occur, and particu- 
jarly as to the nature of the ‘isomeric changes’ involved in the formation 
of many sulphonic acids—an all-important, but seemingly very complex, 
problem. 
Much has been done during the year towards procuring the informa- 
tion needed, especially in the case of the naphthols, which claim attention 
on account of the remarkable ‘ plasticity ’ they manifest—a plasticity that 
seems to distinguish them from all other derivatives of naphthalene, due 
apparently, at least in part, to the readiness with which they are con- 
verted into keto-compounds of the type first discovered by Zincke. 
In order to study the influence of the OH group wndisturbed, i.e., to 
prevent any change taking place in it such as is involved in the formation 
of a keto-compound, numerous experiments have been made with the 
methoxy- and ethoxynaphthalenes in the writer’s laboratory. Dr. Lap- 
worth has very kindly undertaken the study of the sulphonic acids of the 
3-compounds, and his results! form a valuable addition to our knowledge, 
as such substances afford well-defined crystalline sulphochlorides, sulphon- 
amides, &c., a class of derivatives which cannot be prepared from the 
naphthol-acids. One very remarkable result has been arrived at by Dr. 
Lapworth. The initial product formed on sulphonating a cold solution cf 
B-ethoxynaphthalene is the 2: 1 acid in a nearly pure state ; but if the 
product be kept at the ordinary temperature it spontaneously changes into 
a mixture of the 2: 1’ and 2 : 3’ acids, the change being complete, how- 
ever, at the end of twelve to fifteen hours. When /-methoxynaphthalene 
is similarly treated it also yields practically nothing but the 2: 1 acid, 
' Cf. Proceedings of the Chemical Society, 1895. 
