606 Prof. Macallum. Inorganic Composition of the [June 23, 



St. Andrews, New Brunswick, in August of last year, he obtained a 

 quantity of the blood serum of the cod, Gadus callarias, also about 200 c.c. 

 of blood serum from the pollock, Pollachms virens, and about 500 c.c. of 

 blood plasma from three large specimens of lobster, Homariis americanus. 

 Later, through the kindness of the Acting Director of the Station, 

 Prof. Penhallow, considerable quantities of the blood and blood serum of 

 the dogfish, Acanthias vulgaris, were collected and placed at the author's 

 disposal. 



These have been analysed to determine their inorganic composition, and 

 the results, while limited, and therefore inadequate to determine finally the 

 solution of the question, are contributory to that end and are of sufficient 

 interest to justify their publication. 



II.-— 3Iethods of Analysis. 



The methods of analysis followed were on the whole those employed by 

 Bunge in the analysis of the inorganic composition of milk, and subse- 

 quently adopted by Abderhalden in his investigations on the composition of 

 the blood in a number of mammals. Modifications were introduced into 

 these methods as the description of them indicates. 



For the determination of the potassium and the sodium a weighed 

 quantity, varying in volume from 30 to 80 c.c, of the blood or the serum 

 was evaporated to dryness in a large platinum dish and tlien, after being 

 heated for five hours at 115° C. to determine the residue, tlie latter was 

 carefully carbonised at a low red heat till all the volatile organic matter 

 was destroyed. Tlie carbonised residue was then extracted several times 

 with hot water, and the residue, after being dried and incinerated, was 

 dissolved in dilute hydrochloric acid. This latter solution was added to the 

 volume of the extraction fluids, and to the resulting mixture saturated 

 baryta water was added to precipitate the sulpluiric and phosphoric acids ; 

 tlie mixture was filtered, the filtrate reduced in volume l)y evaporation on a 

 water bath, and then treated with crystals of ammonium carbonate to 

 precipitate the calciuu), magnesium, and tlie excess of the barium from 

 the solution. The filtrate from this was evai)orated to dryness in a large 

 platinum dish, the residue fused with anhydrous oxalic acid, then dissolved 

 in water and the solution filtered. Tlie filtrate, containing the carlmnates 

 of sodium and potassium, was now civaporated to dryness in a small platinum 

 capsule, the residue heated to dull redness and then dissolved in 5-8 c.c. of 

 water. If the solution was not clear it was filtered through a filter paper 

 of smallest possible siiiierficial area, the solution again evaporated to dryness 



