I. INTRODUCTION 



1 . GENERAL STATEMENT: The chief purposes pervading researches on 

 the streptococci are two: (i) to get a sound basis for the classification of 

 the different types and (2) to understand the role they play in the general 

 processes of nature. All the results, thus far, are based on the changes 

 which these organisms produce in their environment. Though this in- 

 formation is very valuable we must not forget that in order to compre- 

 hend function we must understand structure and composition . Discovery 

 of the varieties of relation of the actual constituents of the bacterial bodies 

 must lead to a better realization of the very things for which we are seek- 

 ing. With this purpose in view, we have undertaken the work to be de- 

 tailed here. 



2. HISTORICAL: This is not the first study on bacterial composition. 

 Thus Brieger as early as 1885 (i) analyzed pneumococcus cultures; Weyl 

 (2) and Hammerschlag in 1891 (3), Hoffman in 1894 (4) De Schweinitz 

 and Dorset in 1895 (5), 1896 (6), 1897 (7), 1898 (8), Ruppel in 1898 (9) 

 and Levene in 1898 (10) and 1901 (n) investigated the chemistry of 

 Baccilus Tuberculosis; Drymount in 1886 (12) and later Vaughan (13) 

 and Wheeler (14) worked with Bacillus Anthrax. More recently Vaughan 

 (15), Leach (16) and Dawson (17) analyzed Bacillus Coli cultures and 

 Nicholle and Alilaire (18) and Bradley (19) used Bacillus Diphtheria as 

 their material for analysis. 



3. OBJECT OF RESEARCH: Each of these reports supply interesting 

 additions to our knowledge of the chemical make-up of bacteria. It 

 might, therefore, seem that our problem is a very simple one, differing 

 from previous investigation only in respect to the organism, considered. 

 Such a view cannot be more than superficial. Our aim, here, is not merely 

 to gather data on the chemical composition of the streptococcus it is to 

 gather such data under standardized conditions. Practically nowhere in 

 the literature is there mention of such an attempt, though it is precisely 

 the want of standard methods that has made so many results in bacterio- 

 logical work of little or no value. We have, therefore, made special 

 effort to work out details. This will become apparent with a careful 

 consideration of the methods of procedure described below: 



II. CHARACTER OF ORGANISMS 



1. SOURCE: All the strains of streptococci were obtained from root 

 canal infections in the teeth of man.* 



2. PREPARATION OF MEDIA FOR USE IN DETERMINING THE BIOCHEMICAL 

 REACTIONS: 



(a) Sugar-free broth: 75 grams of Bacto-veal in 1000 cc. of tap water 

 were heated in the Arnold sterilizer for two hours and filtered through 

 filter paper. This infusion was inoculated with B. coli communior (20), 

 incubated at 37 C. for 18 hours and sterilized at "Arnold" temperature 

 for 45 minutes. The hot bouillon easily dissolved the 10 grams of peptone 

 and 5 grams NaCl that were added at this point. An aliquot part (locc.) 

 was cooled and adjusted with 0.05 M NaOH to the hydrogen-ion concen- 

 tration, PH = 7.9 (21). The calculated amount of M NaOH was added 



*A11 the cultures were obtained from Dr. M. L. Rhein and Dr. J. M. Levy, New 

 York City. 



