THE PHOSPHATES. 227 



the spleen and the muscular layer of the intestinal canal, which are 

 especially rich in contractile tissues, are also especially distin- 

 guished by the amount of free acid, &c., which they contain ; whilst, 

 on the other hand, the juice of the salivary glands and of the pan- 

 creas, in which Kolliker discovered few or none of these fibre-cells, 

 are distinguished by their alkaline reaction and by their poverty of 

 potash-salts. I have ascertained from direct observation that the 

 middle coat of the aorta and the A. innominata yields far less acid, 

 phosphates, and potash, in proportion to the amount of fibre-cells, 

 than the same tissue from middle-sized arteries. It requires, there- 

 fore,"further and more exact investigations to determine whether the 

 juice of the spleen and similar organs exhibits an acid reaction, &c., 

 simply because it is blended with the juice belonging to the fibre- 

 cells, or whether the presence of these substances is inherent in 

 the organ as such ; but still it must be confessed, that our histo- 

 chemical investigations render the former view by far the more 

 probable. 



We likewise meet with accumulations of phosphates indepen- 

 dently of the presence of free acid, or the formation of acid salts, 

 in parts of the animal body where their presence has either served 

 certain definite purposes, or where it is still regulating certain func- 

 tions ; instead, however, of recurring to the observations we have 

 already made in relation to this subject (see vol. i. pp. 412-418 and 

 440), we will here merely refer to the following facts. All histogenetic 

 substances are almost inseparably combined with considerable quan- 

 tities of phosphates, so that the two are always dissolved together, 

 and are again associated in all coagula or precipitates obtained 

 from their solutions. The bases of all completely developed tissues 

 always contain in their ash considerable quantities of phosphates, 

 which for the most part are in the proportion of 1 equivalent of 

 phosphoric acid to I equivalent of base, and therefore occur as 

 metaphosphates ; as for instance, in the case of the muscular sub- 

 stance, and the substance of the connective tissue of the lungs and 

 of the liver, after being thoroughly rinsed in water according to 

 Liebig's directions. Hence we may conclude, that acid phosphates 

 must have been present in the recent tissue, or rather that a por- 

 tion of the phosphoric acid was combined with organic matters. 

 We have further seen (see p. 135) that all secretions from the 

 blood, which are distinguished by their plasticity, exhibit phos- 

 phates, which although not always present in large quantities, 

 never fall below a certain amount ; and the admirable observations 

 of C, Schmidt have shown that a certain quantity of phosphates is 



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