162 THE PROTEOMORPHIC THEORY AND THE NEW MEDICINE 



THE PREPARATION OF THE PROTEALS 



It is perhaps unnecessary here to go into details concerning 

 the various methods of extracting vegetable proteins that have 

 been employed at one time and another in my laboratory. The 

 chief facts of importance attach to the method that has super- 

 seded others, and has been employed in preparing the Proteals 

 supplied to the profession during the past year, the results of 

 the use of which are summarized in succeeding pages. 



The method consists in the extraction of the proteins by boil- 

 ing the ground seeds or other plant products in a very dilute 

 solution of hydrochloric acid. Best results have been attained 

 with most seeds by using 50 grams of the powder to the liter 

 of water, and adding from 40 to 80 cubic centimeters of ten 

 per cent, hydrochloric acid. With plant products other than 

 seeds, such as alfalfa meal, 20 cubic centimeters of the dilute 

 acid suffice. The mixture is boiled in a glass flask for four 

 hours. 



The decoction contains, of course, a mass of vegetable detritus 

 that must be removed by filtering. There is marked variation 

 in different products in their facility of filtering. With some 

 it is necessary to refilter two or three times. The final filtrate is 

 neutralized with 10 per cent, solution of sodium hydroxide. Just 

 beyond the neutralization point a precipitate forms, part of which 

 is redissolved. The solution, meantime, becomes of a darker 

 color, varying from amber to a deep claret according to the 

 constituents. 



Either before or after filtering, as a matter of convenience, 

 the solution is evaporated at low temperature under a hot air 

 draft until it bulks about 300 cubic centimeters (varying from 

 200 to 400 with different products). The solution has usually 

 become slightly acid again, and it is necessary once more to 

 neutralize with sodium hydroxide. It is important that slight 

 alkalinity should be attained and preserved ; otherwise, the extract 

 will be painful on hypodermic administration. 



The Kjeldahl nitrogen test is now made, after which the solu- 

 tion is either further evaporated or diluted with normal salt 

 solution, as the case may require, to bring it to the standard 

 strength of three milligrams of nitrogen to the cubic centimeter ; 

 indicating a protein content of slightly less than two per cent. 



The extract thus standardized is placed in ampules and sealed 

 in a Bunsen flame ; then sterilized discontinuously for three days 

 in an ordinary sterilizer. 



There are, as a matter of course, tricks of manipulation facil- 

 itating the preparation of the Proteals that vary somewhat with 

 the different products ; but, as will be seen, the process is, on 



