DR. FREDERICK LANGMEAD'S PAPER 333 



that the density of the curd of cow's milk can be 

 modified profoundly by the addition of sodium citrate. 

 This can be demonstrated by a simple experiment. 

 Let three test-tubes be taken and an equal amount of 

 cow's milk be poured into each. Slightly acidify the 

 milk in each tube. Into test-tube No. i drop a 

 measured quantity of rennet ; to the milk in test-tube 

 No. 2 add the rennet and also sodium citrate in the 

 proportion of 2 gr. to the ounce of milk ; and into 

 test-tube No. 3, in addition to the rennet, add sodium 

 citrate in the proportion of 5 gr. to the ounce of 

 milk. Incubate until coagulation is completed and 

 examine all the tubes. No. i will contain a dense, 

 tough, shreddy curd ; No. 2 will contain a soft floccu- 

 lent curd, easily pulping under the finger, and closely 

 resembling that of human milk ; No. 3 will contain 

 little or no curd at all. Sir Almroth Wright, there- 

 fore, suggested that cow's milk to which sodium 

 citrate in the proportion of 2 gr. to the ounce has 

 been added might afford a valuable means of feeding 

 infants. 



To Dr. F. J. Poynton the profession is indebted 

 for putting this proposal to a practical test. His 

 results, published in the Lancet in 1904, were so 

 encouraging that citrated milk has now become widely 

 employed and recognized as a useful method of infant 

 feeding. This observer, however, did not adhere 

 closely to the original suggestion, but combined 

 citration with dilution, using i gr. of sodium citrate, 

 and not 2 gr., to the ounce of milk. 



The advantages of an undiluted milk appeared to 

 me to be so great that I determined to give whole 

 citrated milk a thorough trial, and now, after more 

 than five years' observation of a large number of 

 infants who have been fed in this way, I believe it to 

 be the best form of artificial feeding in all but excep- 

 tional cases. 



The technique is simplicity itself. Sodium citrate 



