1863.] 407 



Fifthly, that the greatest amount of fibrin appears when the albu- 

 men is neutral or slightly acid. 



Sixthly, that the viscidity of the material employed promotes the 

 formation of fibrin. 



Seventhly, that albumen, artificially digested in gastric juice, pro- 

 duces fibrin by its subsequent oxidation, even after dialysis. 



Eighthly, that gluten dissolved in gastric juice, and then oxi- 

 dized at the ordinary temperature, yields fibrin. 



The formation of fibrin in the human body, and its relation to 

 albumen, has long been a vexed question. I venture to put forward 

 these experiments in connexion with this important and interesting 

 inquiry. 



V. "Note on the Spectrum of Thallium.'' By Professor WIL- 

 LIAM ALLEN MILLER, M.D. ,LL.D., Treasurer and V.P.R.S. 

 Received January 15, 1863. 



My friend Mr. Crookes, the discoverer of the new metal thallium*, 

 having kindly put into my hands a small quantity of the metal, which 

 he believes to be chemically pure, I have been enabled to make some 

 experiments upon its spectrum, the results of which may not be with- 

 out interest to the members of the Royal Society. 



Thallium, as is well known, when examined in the usual way by 

 the spectroscope, yields a spectrum of remarkable simplicity, furnish- 

 ing a single intense green line, the occurrence of which, as is familiar 

 to chemists, led Mr. Crookes to the discovery of the metal, and sug- 

 gested to him the name by which it is known. In order to try the 

 effect of a progressively increasing temperature upon the spectrum 

 furnished by the metal and its compounds, the following experiments 

 were made. 



* It has been made the subject of question abroad, whether Mr. Crookes or M. 

 Lamy was the first to recognize the metallic nature of thallium, and thus to 

 dispute the claim of Mr. Crookes to the full credit due to him for his investigation 

 (with only about twenty grains of the element) of its leading characters where no 

 previous clue existed to guide him. It may be sufficient to state in answer to this 

 suggestion, that Mr. Crookes had exhibited it at the International Exhibition, and 

 marked as metallic his scanty store, though in the form of a precipitate, in the 

 beginning of May, unquestionably before M. Lamy had published anything re- 

 lating to thallium. 



