FIBROUS CONNECTIVE TISSUE. 67 



The results of these analyses agree so closely that it is safe 

 to conclude that the several preparations have practically the 

 same composition. Especially noticeable is the low content 

 of sulphur and the small content of ash, two features which 

 may be taken as indicative of the great purity of the products. 

 Undoubtedly the small percentage of sulphur, as contrasted 

 with those in the older analyses, is due to the more complete 

 removal of mucin in these preparations, for, as has been 

 recently found, the sulphur-content of mucin from tendons 

 is quite high, 2.32 per cent.* It is also to be noted that the 

 present analyses show the percentage of sulphur hi this form 

 of gelatin to be even lower than the amount found by Morner 

 in the gelatin obtained from corneal cartilage, 0.3 per cent. 

 Further, the above samples of gelatin give no reaction for mer- 

 captan-sulphur with plumbic acetate and potassium hydroxide. 



In preparation C, phosphorus was determined by fusion 

 with sodium hydroxide and potassium nitrate, etc. The 

 result showed the presence of 0.025 per cent of phosphorus. 

 The ash, however, contained calcium phosphate. Calculating 

 all the phosphorus found to tribasic calcium phosphate would 

 account for less than half the ash. The ash also contained 

 calcium sulphate. Taking the average content of ash and 

 calculating half of it as calcium sulphate would require 0.038 

 per cent of sulphur, an amount too small to materially modify 

 the percentage of sulphur found in the substance. 



Among the earlier analyses of gelatin, or rather of collagen, 

 from white fibrous connective tissue are those of Scherer.f 

 His process of preparation consisted in macerating the tendons 

 in water containing saltpetre, washing repeatedly with water, 

 and finally extracting with alcohol and ether. The average 

 composition of the product was C 50.51, H 7.16, N 18.37, S 

 and O 24.03. 



Hofmeister J prepared a body which he considered identical 



* Chittenden and Gies, The Mucin of White Fibrous Connective Tissue. 

 Journal of Exper. Medicine, vol. i, p. 186. 



t Annal. d. Chcm. u. I'liarm., Bd. xl, p. 46. 



t Ueber die chemische Structur des Collagens. Zeitschr. f . physiol. Chem, 

 Band ii, p. 299. 



