CALCIFICATION. 49 



Before considering the phenomena of calcareous infiltration, 

 we must settle a question, on the due answering of which so 

 much depends, that it may justly be regarded as fundamental. 

 How are calcic phosphate and carbonate held in solution by 

 the blood and the juices of the parenchyma ? and what may we 

 regard as the probable conditions which determine their precipi- 

 tation in the tissues ? 



Our answer to this question is fragmentary. From the inti- 

 mate combination of minute quantities of calcic phosphate with 

 all the albuminates (the salt remaining after their calcination as 

 a residual ash), we may infer that it is chemically bound up with 

 albuminates in all the nutrient fluids of the animal oro-anism, 

 and that, when so combined, it is soluble in water (^Gorup- 

 Besanez). Apart from this hypothesis we have the significant 

 fact that calcic phosphate, and still more, calcic carbonate, are 

 soluble in liquids containing free carbonic acid. The blood and 

 nutrient fluids of the organism fulfil this condition. Hence it is, 

 to say the least, not improbable that frefe carbonic acid is an 

 important, perhaps the most important, agent in the solution of 

 the earthy salts. 



Unsatisfactory as it is to have to give a hypothetical answei 

 to the first part of the question, we find ourselves in a far more 

 puzzling predicament when we attempt to give an adequate 

 explanation of the causes which determine the precipitation of 

 these salts. But the attem2:)t must nevertheless be made. The 

 roundabout but only eff'ective way to get at a solution of the 

 problem is to consider all the known examples of calcification 

 one by one, with a view to finding out what the various localities 

 in which we find calcium salts precipitated have in common ; 

 and, further, how this common property adapts them for becoming 

 depositaries of these salts. We must be careful to eliminate all 

 those cases of calcareous infiltration in which a simultaneous 

 reabsorption of calcium salts from the osseous system is taking 

 place, and in which, therefore, we are led to infer with certainty 

 that the blood is saturated with them, that there is a true " calcic 

 dyscrasia." Such cases must be excluded, inasmuch as it is 

 obvious that, the blood being capable of holding only a limited 

 proportion of calcium salts in solution, precipitation must ensue 

 at some point or other, after the limit of saturation has been 

 reached. We must confine ourselves to the consideration of cal- 



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