Tests with Precipitins 389 



Biondi (1902) obtained reactions with blood stains on rusty knives, 

 on leather, and on fabrics exposed to the rain. Blood stains washed 15 

 and 30 minutes at 70 and 80 C. respectively gave no reaction, whereas 

 they had to be washed some hours at low temperatures to remove all 

 traces of blood as evidenced by the reaction with antiserum. He found 

 that strong acid, 5 minutes contact with 5/ carbolic, and 1 : 1000 

 sublimate or chloride of lime, caustic potash, soap, and borax destroyed 

 the reacting substance. 



Whittier (18. I. '02) and Wood (24. iv. '02) have used the precipitin 

 test in medico-legal cases in America with positive result. Okamato 

 (x. 1902) testing various human blood-stains obtained negative results 

 in about j of them, all animal bloods giving negative results when 

 tested by anti-human serum. He found very old and putrid blood 

 generally to give a negative result. The papers of several other authors, 

 bearing indirectly upon this subject, will be found mentioned under the 

 tests with various haematosera p. 161 et seq. 



In some tests which I conducted together with Mr Sanger and which 

 are mentioned in his Thesis' (23. xn. '02) it was found in several 

 instances that blood spots on leather, owing to the varying acidity of 

 leather, at times gave pseudo-reactions, that is, such blood dilutions gave 

 a clouding upon the addition of any serum. Sanger found that it was 

 possible to neutralize this acidity and obtain positive specific reactions, 

 neutralization being effected by the addition of '1 / sodium carbonate. 

 The studies upon the effect of various agents on blood were continued 

 by Graham-Smith, and are cited fully on pp. 7686, 390 et seq. 



Farnum (28. xn. 1901) obtained antisera by injecting semen intra- 

 peritoneally into rabbits, or using testicular emulsions, derived from 

 man, dog, and bull. The injections were made at intervals of 5 6 days, 

 the rabbits receiving 5 8 injections of 5 to 10 c.c. at a time. The 

 antisera were specific, when tested on the semens mentioned. Anti- 

 human serum produced a reaction with human serum dried as long as 

 34 days. 



Layton (1903, p. 220) obtained positive results with anti-human 

 serum tested on fresh human blood-stains on doth and filter-paper, old, 

 dried stains on cloth, newspapers, filter-paper, putrid blood and blood 

 soaked in earth. Also with human blood mixed with others as m 

 Nuttall's earlier experiments. He does not state the age of the blood- 

 stains he tested. 



1 Incorporated in the Paper by Graham-Smith and Sanger, the main results of which 

 are reprinted in this book, having appeared in the Journal of Hygiene, vol. in. 1903. 



