440 TRANSACTIONS OF SECTION B. 
continued during a long series of years, so muchi is owing. The synthetic 
work carried out with brilliant success in recent years by W. H. Perkin 
may also be referred to as of extraordinary promise but of wellnigh incon- 
ceivable difficulty. 
Before leaving this chapter reference should be made to the almost 
protean character of camphor, as disclosed by the work of inquirers such 
as Kipping, Pope, Forster, Lapworth, and Lowry; no other substance has 
lent itself to use in quite so many directions and with such fruitful results. 
Special mention may be made of the demonstration which Pope has given, 
with the aid of the camphor-sulphonic acids, that nitrogen, sulphur, 
selenium, and tin give rise to optically active substances in all respects 
analogous to those furnished by carbon. The success with which Kipping’s 
arduous labours have been crowned is also very noteworthy, taking into 
account the many difficulties he has overcome in preparing optically active 
silicon compounds. The extension of the Pasteur-van’t Hoff theory of 
asymmetry inferentially to all elements which are at least quadrivalent, 
now accomplished, is of superlative importance. 
Lowry’s refined observations on the conditions which determine the 
interconversion of isodynamic forms of some of the camphor derivatives 
may also be cited as of special value as a contribution to the study of 
metamerism and the conditions which determine chemical change generally. 
Not the least interesting feature of camphor is the light thrown by its 
behaviour on the influence which oxygen exercises as an attractive element 
and on the part which spatial configuration may play in determining 
directions of change. It is clear that, whatever the agent, the attack is 
always delivered from the oxygen centre and that the direction in which 
the attack becomes effective depends on the position which the agent can 
take up relatively to the various sections of the molecule.’ 
It must be confessed that our efforts to penetrate behind the veil in the 
case of the higher carbohydrates—starch and cellulose in particular—have 
not been rewarded with success. 
Moreover, though inuch has been done of late years to unravel the nature 
of the vegeto-alkaloids, substances such as quinine are still only partially 
deciphered and not one of the more complex alkaloids has been produced 
synthetically. In view of the fact that quinine is still the one effective 
and practically safe anti-malarial medicine, the disclosure of its constitution 
is much to be desired. The isolation of adrenaline from the suprarenal 
capsule and the discovery that this alkaloid—-which is an extraordinarily 
active substance physiologically—plays a most important part in controlling 
vital processes is of supreme interest. Other glands—the pituitary gland, 
for example—appear to contain peculiar active substances which are of 
particular consequence in regulating animal functions. The discovery of 
such substances affords clear proof that life is largely dependent on what 
may be termed chemical control. 
In addition to indigo, the simpler yellow and red natural colouring- 
matters have now been thoroughly examined but this class of substance still 
affords abundant opportunity to investigators. Kostanecki’s comprehensive 
studies of the xanthone group may be referred to as of particular value. 
Attention may be directed here to the investigation of brazilin and 
haematoxylin by W. H. Perkin and his various co-workers, not merely as 
being full of interest and importance as a contribution to our knowledge 
of the relation between colour and structure and as a brilliant example of 
technical skill, but because of the illustration it affords of the extreme in- 
tricacy of such inquiries and of the vast amount of labour they entail. The 
general public probably has not the slightest conception of the difficulties 
which attend such research work and of its costliness. 
' Cf, Chen. Soc. Trans,, 1902, 81, 1469, 
