CHAP. VII.] THE CONNECTIVE TISSUES. 285 



METHODS FOLLOWED IN THE QUANTITATIVE 

 ANALYSIS OF BONE. 



i The bones to be analyzed are carefully denuded 



ry prepara- f thejr periosteum. They are then divided with a saw. 



tion of bones The cancellated tissue is carefully removed, by means 



to be subject- of a chisel, from the compact bone, and the latter 



L to analy- j s t ] ien divided into somewhat small pieces. Each 



of these is then wrapped in paper and being placed 



on an anvil is struck with a hammer so as to crush it into minute 



fragments. These are then powdered in a steel mortar and the 



powder passed through a very fine sieve. 



Some writers recommend that the crushed bones should, before 

 pulverization, be tied in a small muslin bag which is suspended 

 in distilled water, which is to be renewed several times, with the 

 object of separating from the bone soluble constituents which do 

 not properly belong to it, but which are of the nature of accidental 

 contaminations. If this process be followed, the fragments of bone 

 after extraction with cold water are dried in an oven and thereafter 

 pulverized. 



Determination of the quantity of Fat in Bone. 



A weighed quantity of powdered bone which has been dried 

 at 130 C. is extracted with ether as in the apparatus of Drechsel 

 (see p. 265). The ethereal solution is evaporated to dryness and 

 weighed. 



Determination of the total quantity of Ash in Bone. 



A quantity of the fat-free powder which has been dried at 

 1 30 C. is weighed in a platinum crucible and ignited until the ash 

 is perfectly white. The residue is moistened with solution of 

 ammonium carbonate, and then heated gently. The object of 

 this operation is to restore the carbon dioxide which may have 

 been expelled from the bases by the strong heat to which they have 

 been subjected. 



Determination of the quantity of Chlorine in the Ash. 



The ash resulting from the preceding operation is finely powdered 

 and dissolved, with the aid of heat, in dilute nitric acid. The 

 solution is concentrated and then treated with silver nitrate, which 

 precipitates all the chlorine as silver chloride. This is washed 

 by decantation, ignited and weighed according to the ordinary 

 rules of analysis. 1 part of AgCl corresponds to '2 47 24 parts of 

 chlorine. 



