'608 Prof. Macallum. Inorganic Composition of the [June 23, 



•copper, as was the case when the preparation was derived from Crustacean 

 blood serum, sulphuretted hydrogen gas was passed, the sulphide of copper 

 formed was separated by filtration, and the copper determined as CU2S or 

 •CuO. The filtrate from this, after being boiled for some minutes to drive 

 ■off the dissolved sulphuretted hydrogen, was nearly neutralised, acetic acid 

 •and crystals of ammonium oxalate were added, and, after standing for some 

 hours, the calcium oxalate precipitate was removed and weighed either as 

 •CaO or CaS04. From the filtrate the magnesium was precipitated as 

 magnesium phosphate by the addition of ammonium phosphate and 

 ammonia. 



In the case of the solutions made as described from the ash of Vertebrate 

 blood or serum, ammonium acetate was added, and the mixture allowed to 

 stand for 24 hours in order to precipitate some of the iron and all the 

 phosphoric acid as ferric phosphate, which was removed by filtration. If 

 there still remained iron in solution (as in the case of Vertebrate blood), the 

 fluid was rendered alkaline with ammonia, the resulting precipitate of oxide 

 of iron, lime, and magnesia was removed by filtration and, while still moist 

 ■on the filter, extracted several times with a hot solution of ammonium 

 chloride, which dissolved out the lime and magnesia and left the ferric oxide. 

 The extract containing the dissolved lime and magnesia was added to the 

 filtrate previously obtained, the whole reduced in volume by evaporation, 

 the calcium precipitated as oxalate and from the filtrate the magnesium as 

 phosphate in the usual way. 



Kecognising that the precipitate of calcium oxalate obtained in each case 

 might, in spite of the method of separation used, contain also some magnesium 

 oxalate, it was incinerated, the ash dissolved in acetic acid, and ammonium 

 oxalate added to the solution to precipitate the calcium, which was weighed 

 as lime or as sulphate. Tlie filtrate from the precipitate was then appro- 

 priately treated, to separate and estimate the traces of magnesium present. 



For the determination of the chlorine, 1-2 grammes of sodium carbonate 

 were added to a weighed quantity of the scrum or blood contained in a 

 platinum dish, the mixture, after being carefully stined, was evaporated to 

 dryness, and the residue thoroughly carbonised at a dull red heat. The mass 

 was extracted with hot Avater several times, and then completely incinerated 

 at a li)\v luvit. The ash was dissolved hx cold dilute nitric acid, the solution 

 filtered, and the liltrate added to the volume of the extracts previously 

 obtained. The chloiine in this was determined as chloride of silver in the 

 usual way. 



'J'lie sulj)huric acid was determined only in tlie blood of the lobster and 

 i>\ tin; liorscHlioe crab {L'miil ii;<). A weighed (puuitity of the hlood was 



