266 ANNUAL OF SCIENTIFIC DISCOVERY. 



The low price of wood spirit will, we are sure, induce many photog- 

 raphers to test the matter. Bulletin de la Soci6t6 Lidustriette de 3Iul- 

 house. 



ON THE DETECTION OF BLOOD, CONSIDERED IN A CHEMICO-LEGAL 

 POINT OF VIEW, BY M. MORIN, PROFESSOR OF CHEMISTRY AT 

 THE MEDICAL SCHOOL OF ROUEN, FRANCE. 



The existence of blood on the clothes of an assassin constitutes one of 

 the most important problems of judicial chemistry. The action of reagents 

 and the power of the microscope, in many cases, demonstrate the presence 

 of the organic liquid, provided that the criminal has not washed his clothes 

 with the precautions that science has placed at his disposal, or else that 

 the blood deposited on the bodies which have served him. as supports has 

 not undergone putrid fermentation, so as to destroy its characteristic ma- 

 terials. 



The assassin, in his haste to destroy that which is frequently an essential 

 portion of the evidence against him, washes his clothes with boiling water, 

 sometimes even with the addition of soap, with a view of hastening the 

 disappearance of this indubitable evidence of his crime ; whence results 

 the fixation of certain matters of the blood on the tissue. This liquid, 

 thus concreted, gives to the stained part a greater consistence than that of 

 the tissue itself, and forms stains of a more or less deep-brown color. 

 These stains are of two kinds ; sometimes they arise from a jet of blood, 

 at others they are imbibed ; sometimes the former have, so to speak, a 

 spheroidal form, and this happens when the blood faces on a tissue pro- 

 vided with small fibrils which retain it, and seem to be opposed to its 

 juxtaposition, by favoring its coagulation. If, on the contrary, the tissue 

 is free from nap, the vital fluid, by retaining for a longer time its tempera- 

 ture, and in some measure its vitality and its fluidity, forms stains by im- 

 bibition. Whatever may be their state, when they are washed at a tem- 

 perature higher than albumen coagulates they present the same color. 



The ordinary means of demonstrating the presence of blood upon a 

 tissue consist in the immersion of the stains in distilled water, with a 

 view of obtaining a solution of this coloring matter with some proteic 

 elements ; but this method of investigation is impracticable in the case of 

 stains which have been washed with boiling water. To solve this problem 

 we have made some experiments, which we now communicate. We re- 

 ceived human blood, issuing from a vein, upon linen ; the tissue was im- 

 mediately saturated with that liquid, and after some hours' exposure to the 

 air stains were obtained, which were more consistent than the other por- 

 tions of the tissue. They were washed with water at a temperature above 

 that required for the coagulation of the albumen. The stains thus acquired 

 a duller tint than they had previously. After this washing in ordinary 

 water, they were subjected to the action of boiling water containing soap, 

 and finally to that of cold water, until the liquor was no longer milky. In 



