342 REPORT—1904. 
Many of them were tried in the presence of osmotic pressure-free proteid, 
but again the results were negative. 
Finally two nucleic acids (prepared quite free of proteid), the one from 
yeast, the other from thymus gland (adenylic acid of Kossel and Neumann), 
were found in neutral solution in sodic or ammonium hydrate to give a 
lasting osmotic pressure on the membrane used in the proteid experiments. 
It is, of course, not maintained that nucleic acid is the substance which 
gives rise to the osmotic pressure of serum against its filtrate through 
gelatine, but the result indicates that such a gelatine membrane may be 
quite impermeable to certain substances in true solution. 
Other experiments have been conducted with a specially purified 
caseinogen taken up in lime water to form the so-called neutral and basic 
calcium caseinogenates. The former clotted with rennin and became more 
opalescent at 40° C., clearing again on cooling. 
Neither of these preparations gave any osmotic pressure, and are there- 
fore considered as hydrosols and not as true solutions. 
Finally a series of experiments with hemoglobin have been instituted, 
but are not yet completed. The spectrophotometer has been used 
throughout, and no product used for osmometric work unless giving the 
Hiner constants in two regions of the spectrum. The onset of warmer 
weather and the removal of the laboratory to other premises have put an 
end to the further prosecution of this part of the work, but it is intended 
to take it up again next session. 
The Physiological Hffects of Peptone and its Precursors when Introduced 
into the Circulation.—Interim Report of the Committee, consisting 
of Professor EH. A. ScHAFER (Chairman), Professor W. H. 
THompPson (Secretary), Professor R. Boyce, and Professor C. 8. 
SHERRINGTON. 
Tur METABOLISM OF ARGININ. 
In previous experiments it had been ascertained that arginin in the form 
of a neutral solution of its carbonate may be injected into the circulation 
of a dog without producing harmful, or, indeed, any pronounced effects. 
It proved inert as regards blood pressure, and had no immediate influence 
upon urinary secretion, beyond that which could be attributed to the 
solvent employed. 
In the following experiments arginin was administered to dogs either 
hypodermically or with the food, and its effects upon nitrogenous meta- 
bolism observed. When submitted to the action of barium hydrate, arginin 
readily undergoes hydrolytic cleavage, and yields urea and ornithin (di- 
amido-valerianic acid). 
/NEL NH: CH,.NH, 
= + (CH»)» 
ONH Toe Hiss a OHH 
\NH.CH, \NH, Coigene 
(CH). ri: 
CH.NH, 
CO.OH 
That is to say, half the nitrogen of arginin appears as urea and half as 
