762 'transactions of section i. 



and in Exp. V. to 15 per cent, of the extract nitrogen given. Further, on 

 examining the nitrogen of the faeces, it will be seen that in all cases the effect 

 of the extract was to lessen the amount excreted, and therefore to increase 

 the assimilation of the biscuit food. 



As regards the form in which the extra nitrogen was excreted in the urine 

 during the periods of feeding with beef extract and egg-white, it was found that 

 proportionately less appeared as urea and more as kreatinin and kreatin in the 

 former than in the latter. The egg-white did not increase the total kreatinin 

 or kreatin, on the contrary seemed to reduce the amount of these substances 

 in the urine. 



In Exp. V., Period 1 (biscuit), the urinary nitrogen contained 73 - 57 of urea 

 and 3.87 per cent, of kreatinin. In Period 2 (extract), the corresponding amounts 

 were 7232 per cent, and 4'7 per cent, respectively ; while in Period 3 (egg-white) 

 the urinary nitrogen contained 74"22 per cent, of urea and 3T per cent, kreatinin. 



The general conclusions seem to be that the beef extract used has both a 

 direct and an indirect nutritive value, apart from any effect it may have as a 

 vascular stimulant. The former leads to relatively large increase of weight in 

 proportion to the amount of foodstuff given. The latter is manifested by a fuller 

 utilisation of the other food constituents to which the extract is added, and is in 

 accordance with Pavlov's observations to the effect that meat extracts promote 

 an increased flow of active digestive juices. The experiments were undertaken at 

 the request of the medical commissioner of the Local Government Board in 

 Ireland with the object of ascertaining whether the extract in question had any 

 nutritive value or not. 



p.S. It was mad© known to the Section that in the experiments a com- 

 mercial extract was used, but as the proceedings of the British Association 

 meetings appear in the Press next day, it was considered necessary to withhold 

 the name until the results were communicated to some other scientific society 

 and published elsewhere. There can be no harm in adding now that the 

 extract of beef used was that known as ' Bovril.' The samples were bought on 

 the market as required and were found on analysis to be very uniform in com- 

 position. — December 6, 1910. 



10. The Conditions necessary for Tetanus of the Heart. By John Tait, M.D. 



11. Neurogenic Origin of Normal Heart Stimulus. By John Tait, M.D. 



12. Report on Body Metabolism in Cancer. — See p. 297. 



13. Report o:i Mental and Muscular Fatigue. — See p. 292. 



14. Demonstration of Calorimeter. By Professor J. S. Macdonald, B.A. 



MONDAY, SEPTEMBER 5. 



Joint Discussion with Sections B and K on the Biochemistry of 



Respiration. 



(i) Problems of the Biochemistry of Respiration in Plants. 

 By Dr. F. F. Blackman, F.R.S. 



As an introduction to this conjoint meeting, a sketch may be given of thy 

 main problems of the biochemistry of respiration in plants. 



