3G8 SECTIONAL TRANSACTIONS.— I. 



may be responsible for observed variations in the velocity of the pulse wave, a simple 

 device was adopted. A bandage of known width was applied to a limb and the 

 pressure of the bandage raised to p mm. of Hg : the effective pressure inside the 

 artery was then not P, the blood pressure as usually observed, but P — p. The pulse 

 velocity can then be measured at varying effective pressures. A curve has been 

 drawn relating the effective pressure to the arterial extensibility. 



Mr. C. J. Bond, C.M.G. — On the Effect of Certain Radiated Lipoids on the 

 Cellular Constituents of the Blood. 



When blood is incubated in a closed cell on an ergosterol film, half of which has 

 been exposed to U.V. rays from a mercury vapour lamp, the red blood corpuscles in 

 the radiated area undergo haemolysis, while leucocytic emigration is also stimulated, 

 and the leucocytes show marked changes. 



This agglutinative and hemolytic effect on the red cells can be used as a test for 

 the presence of radiated fatty substances in smears or extracts from organs and 

 tissues, in blood serum and in other materials. 



Thus, while lanolin and some other fats give a similar result to ergosterol, extracts 

 and smears from the cells of some animal organs give an opposite effect, and show the 

 hsemolytic change in the non-radiated area of the film. Of the organs so far examined, 

 smears from liver cells give the most marked results. 



Radiated Blood Serum. 



Some blood serum (C.J.B.) was evaporated to dryness in the cell of a hollow- 

 ground slide. Half the film of this desiccated serum was then exposed to the U.V. 

 rays from a mercury vapour lamp for half-an-hour. The whole cell was then filled 

 with a suspension of washed native red cells in normal saline, and sealed with a cover 

 glass. 



On standing, the red cells undergo agglutination over the whole film, but much 

 more so in the radiated part. 



Blood serum so treated by concentration and radiation thus acquires the property 

 of agglutinating native red cells. 



Further experiments show that, by concentration in air and by subsequent 

 radiation, the blood serum of an individual belonging to one blood group can be 

 converted (as regards agglutinating capacity) into that of another group. 



This change in the blood serum can also be brought about by repeated agitation 

 in a test tube, in contact with air. 



In the same way blood serum which has been evaporated to dryness in the air 

 retains its increased agglutinative capacity when redissolved in serum or in N.S. 



By the use of concentrated and radiated blood serum, it is possible to show on 

 the same film the presence of rouleaux-formation, agglutination, and haemolysis. 

 Light is thereby thrown on the nature of hemagglutination. 



Prof. H. S. Raper, C.B.E. — The Direct and Indirect Oxydases. 



Recent investigations on the action of tyrosinase have shown that from the 

 phenols and allied substances on which it acts ortho-quinones are produced. In 

 certain instances these turn guaiacum tincture blue without addition of hydrogen 

 peroxide. Since a similar production of ortho-quinones may take place in plants 

 under the action of tyrosinase, which itself does not turn guaiacum blue, the guaiacum 

 reaction is not a correct indicator of the presence of ' direct oxydases.' The 

 classification of oxidising enzymes based on the guaiacum reaction is, therefore, 

 fallacious. 



A study of other reactions which may be used to distinguish these aerobic oxidising 

 enzymes leads to the conclusion that up to the present only two have been shown to 

 exist, namely, tyrosinase and peroxydase. The direct blueing of guaiacum shows- 

 only the presence of certain peroxides or an oxidation system that can produce them 

 in presence of air. 



Prof. J. W. McLeod. — Variations in Respiratory Mechanism amongst 

 Bacteria. 



