1883.] Formation of Uric Acid in the Animal Economy. 63 



II. " Preliminary Note on the Action of Calcium, Barium, and 



Potassium on Muscle." By T. Lauder Brunton, M.D., 

 F.R.S., and Theodore Cash, M.D. Received February 13, 

 1883. 



It lias been shown by Ringer that calcium prolongs the contraction 

 of the frog's heart. This prolongation is diminished by the subse- 

 quent addition of potash. 



It occurred to us that calcium and potassium salts might exercise a 

 similar action on voluntary muscle. On trying it, we found this to be 

 the case. Calcium in dilute solution prolongs the duration of the 

 contraction in the gastrocnemius of the frog. Potassium salts subse- 

 quently applied shorten the contraction. We have been led to try the 

 effect of barium on muscle by considerations regarding the relations of 

 groups of elements, according to Mendelejeff's classification, to their 

 physiological action. These considerations we purpose to develop in 

 another paper. The effect of barium is very remarkable. It produces 

 a curve very much like that caused by veratria, both in its form and 

 in the modifications produced in it by repeated stimuli. We have 

 found that the veratria curve is restored by potash to the normal in 

 the case of the gastrocnemius, just as Ringer found it in the case 

 of the frog's heart. The peculiarity which barium produces in the 

 gastrocnemius is also abolished by potash. We have tested a number 

 of other substances belonging to allied groups, and find that some of 

 them have a similar, though not identical, action with barium. The 

 results of these experiments, as well as the general considerations to 

 which we have already alluded, we purpose to discuss in another 

 paper. 



III. " On the Formation of Uric Acid in the Animal Economy 

 and its relation to Hippuric Acid." By Alfred Baring 

 Garrod, M.D., F.R.S. Received February 15, 1883. 



(Abstract. ) 



The results which have been arrived at, and discussed in this com- 

 munication, may be summed up as follows : — 



Introduction. — The solubility of uric acid and of some of its more 

 important salts at the temperature of the healthy human body has 

 been determined and arranged in a tabular form. These figures may 

 be useful for future reference. 



The action of urates of ammonium and sodium upon chlorides and 

 phosphates of the same bases, when mixed with each other in different 

 proportions, has been ascertained. 



