TRANSACTIONS OF SECTION I. 983 
Knoll’s ingenious apparatus, by which he recorded the eye movements in brain 
anemia. These observations may have some practical significance from the fact 
that there are some cases on record of impairment of the movements of the eyes 
in middle ear disease, and also from the fact that certain ophthalmic surgeons hold 
that Meniére’s disease, or auditory vertigo, is not due to a primary ear lesion, but 
to defective balance of the extrinsic muscular innervation of the eye. 
MONDAY, SEPTEMBER 21. 
The President’s Address (see p. 942) was delivered, and was followed 
by a discussion on the ‘ Ancestry of the Vertebrata’ at a joint meeting of 
Sections D, H, and I. 
TUESDAY, SEPTEMBER 22. 
The following Papers were read :— 
1. Photometry and Purkinje’s Phenomena. 
By Professor J, B. HAycrarr, 
2. The Physical Basis of Life. By Professor F, J, Atuen, ID, Cantab, 
The most prominent function of living matter is what may be called Trading 
in Energy—i.e., the occlusion of radiant energy, storage thereof in the potential 
form, and subsequent dispersion in the form of heat, mechanical work, &c. 
The explanation of this function is to be sought in the peculiar properties of 
nitrogen. The most salient feature of nitrogen compounds is their liability to 
change their constitution under slight variations in the energy equilibrium of their 
surroundings, So wavering is the state of nitrogen under the conditions present 
on our planet, that it may be called the Critical Element. 
The importance of carbon must not, however, be underrated. Its main function 
is the storing of energy. In this function it is largely assisted by hydrogen. 
Oxygen is the medium of exchange between the three other elements just 
mentioned, 
The elements N, O, C, and H may be called the dynamic elements, because 
they are the chief agents in the trade in energy; but their action may be 
intimately dependent on the assistance of other elements present in living matter. 
The properties of living matter seem to indicate that— 
1, Every vital phenomenon is due to a change in a nitrogenous compound, and _ 
indeed zm the nitrogen atoms of that compound. 
2, There is no vital action without transfer of oxygen, and the transfer is per- 
formed by nitrogen (often assisted by iron). 
3. In the anabolic action of light on plants, the nitrogen compounds are affected 
primarily and the CO, and water secondarily. 
4, In the living and active molecule the nitrogen is centrally situated and often 
in the pentad state. In the dead molecule it is usually peripheral and in the triad 
state. 
5. The oxygen store of the living molecule is more or less united with the 
nitrogen, but passes to some other element at death. 
6. The nitrogen of the living molecule is combined in a compiex and perhaps 
changeable manner, the compound resembling in some respects the cyanogen 
compounds, in other respects the explosives such as nitroglycerine ; other analogies 
are also traceable, 
