54 IMMEDIATE PRINCIPLES OF THE TISSUES. 



rachitic bones ; but this is not yet certain. It is probably held in 

 solution by the alkaline salts, already described. It is obtained 

 from the water drunk. It is, perhaps, evacuated in small quantity 

 in the urine ; or is decomposed into some other salt of lime, and 

 one of the sulphates just mentioned. 



10. Subphosphate or Basic Phosphate of Lime. 

 (Phosphate of Lime of the Bones 8Ca0.3P0 5 .y 

 The ashes of every tissue and fluid in the body of man and the 

 mammiferse contain this salt, while some of them have it for their 

 principal constituent, so far as the mass is concerned. It consists 

 of eight parts of the base combined with three parts of the acid. 

 All calcareous deposits, as well as many urinary calculi, and phos- 

 phatic gravel, contain this salt. We have seen that in all cases this 

 exists where the carbonate of lime does. It is the phosphate of 

 lime which forms most of the calculi around foreign bodies intro- 

 duced into the bladder, and those of the prepuce, and which is 

 deposited on instruments left for a time in the bladder. It forms, 

 often by itself, or with the ammonio-magne- 

 sian phosphates, the urinary sand; and pros- 

 tatic calculi are formed of it alone. Uterine 

 and vaginal concretions consist of this, with 

 a little animal matter around some nucleus 

 introduced from without. A calculus of this 



Phosphate of lime calculus, from salt is shown by Fig. 4. 



the bladder. .. ,, .. . .. 



The quantity of phosphate of lime varies 



in different parts. In bones there is 48 to 59, and in enamel even 

 88 J, per cent. ; in dry muscular fibre, .93 to 1 'per cent. ; in coagu- 

 lated albumen (from the blood), 1.8 per cent.; and in fibrine (from 

 venous blood), .69 per cent. It is also a constituent of caseine, 

 globuline, and cartilageine ; and of osteine in the white fibrous 

 tissue, as well as in bone. In the ashes of urine are 2.57 per cent., 

 and of solid feces 12.78 per cent. But the more a part is submitted 

 to mechanical influences, the more phosphate of lime is deposited. 

 Thus there is more in the bones of the lower than the upper ex- 

 tremities (in the same weight), and less than in either in the more 

 passive ribs. The eburnation of bone is generally said to be an 

 illustration of the same principle ; though Lehmann found less than 

 the normal amount of this salt in this condition. But when this 



1 Heintz finds the formula to be 3CaO,PO. 



