Mr Myers, The Standardisation of Antivenomous Serum. 331 



to neutralise 012 mgrms. of the poison. When 0*175 c.c. was 

 used the animal died in 3 hours. The latter method therefore is 

 much more accurate. 



This method of standardisation with unheated Cobra poison 1 

 is simpler and more exact than that at present in use, and can 

 be used by the general practitioner in testing his serum for 

 clinical purposes. We may for convenience call a unit of im- 

 munity that quantity of antitoxin which neutralises ten times 

 the minimal lethal dose for a mouse weighing fifteen grams. 

 A serum, for example, of which 0"2 c.c. were required, would 

 contain 5 units per c.c. 



This method does not reach any great accuracy ; and this is 

 doubtless due to the weakness of the antitoxin. When it is 

 possible to standardise this serum with 100 times the minimal 

 lethal dose, much greater accuracy will probably be possible. 



I wish here to express my thanks to Prof. Ehrlich, at whose 

 suggestion this work was begun in his laboratory last year, and to 

 whom I am indebted for much assistance and advice. 



On a certain Diophantine Inequality. By Major Macmahon, 

 R.A., F.R.S. v. Transactions, Vol. xix. 



[Read 21 May 1900.] 



On rational space curves of the fourth order. By Mr Rich- 

 mond, v. Transactions, Vol. xix. 



[Bead 21 May 1900.] 



i The effect of heating a solution of Cobra poison (1 c.c. = 1 mgrm. in physiological 

 saline solution) to 73° C. for half-an-hour I have found to be as follows. The 

 minimal haemolysing dose for human blood is raised to 20 times the previous 

 quantity. The minimal lethal dose for mice is doubled. The power of the toxin 

 of combining with the antitoxin is diminished, but not nearly to the same de gree 

 to which its toxic power is weakened. 



