1891.] A New Test for Albumin and other Proteids. 

 With this dilute fluid various tests were tried : 



371 



Salicyl-sulphonic acid = marked opalescence at once. 

 Boiling after faint acidulation with acetic acid = no reaction. 

 Heller's test = no reaction at once. Distinct film at junction of 



the two fluids in a few minutes. 

 Xantho-proteic test = no appreciable results. 

 Mercuro-potassic iodide = marked cloudiness. 

 Saturated salt solution with hydrochloric acid (Roberts' test) = 



marked cloudiness. 



Serum diluted to 1 in 10,000 : 



Salicyl-sulphonic acid = distinct cloudiness (especially after 

 | 1 minute), recognisable on comparison with the control tubes 

 in a suitable light. 



Boiling after faint acidulation = no reaction. 



Xantho-proteic test = no reaction. 



Mercuro-potassic iodide = no reaction. 



Roberts' test = no reaction. 



Copper sulphate and caustic potash (Piotrowski's) = no reaction. 



Heller's test = no reaction at the time nor twenty minutes after- 

 wards. 



The amount of proteid present in these dilute solutions is, approxi- 



itely, as follows : 



Taking the percentage of total proteids in ox serum as 7'5,* the 



im diluted to the degree of 1 in 1000 would contain less than 

 of proteid in 13,000 ; while with the dilution of 1 in 10,000 



amount of proteid would be about 1 in 130,000. 



B. Derived Albumins. 



(a.) Acid Albumin. A solution of acid albumin, obtained from a 

 lution of white of egg by the addition of a few drops of a dilute acid 

 subsequent warming, gives a copious precipitate on the addition 

 salicyl-sulphonic acid. 



(&.) Alkali Albumin. A solution of this proteid, obtained by 

 iting the white of egg solution with a dilute alkali, also yields 

 abundant precipitate on being tested with salicyl-sulphonic acid. 



C. Globulin. 



A solution of globulin obtained from blood serum (by precipitating 

 ith magnesium sulphate, and subsequently redissolving in dilute 

 It solution) gives results similar to albumin. 



* Hammarsten, " Ueber das Paraglobulin," ' Pfluger's Archly,' 1878. 



