CHEMISTRY. 277 



analysis, the formula. KO, 2HO, PO. We obtained this salt in a crystallized 

 condition by treating the muscles with weak alcohol and evaporating the 

 liquor to a syrupy consistence. 



While determining the proportion of this salt in the muscles of different 

 animals, we observed evidence of some connection with the formation of the 

 osseous system ; that is, we always found it largely in animals in which the 

 bones are very much developed, and very slightly in the Articulata and 

 Mollusca, The part which this salt takes in the formation of bones is now 

 clear ; for we have directly ascertained that in reacting on carbonate of lime, 

 the phosphate of potash from the muscles forms the basic phosphate of lime, 

 which is so considerable a part of the bony substance. This phosphate of 

 potash is not, perhaps, without effect in the production of a phosphuretted 

 fatty matter that exists in the muscles which will be mentioned farther on ; 

 we think, however, that under these circumstances it deserves the attention 

 of physiologists. The muscles of the vertebrated animals are impregnated 

 with a considerable quantity of fatty bodies made up of varying proportions 

 of olein, margarin, and stearin. Besides these neutral fatty bodies, another is 

 always found, which differs from the substances properly called fat by a 

 number of peculiarities, and presents some analogy to the cerebral fat. "We 

 have made a tolerably complete examination of this interesting substance. 

 It was extracted easily by treating the muscles with weak alcohol, which 

 dissolves it without altering the other fatty bodies. This liquid, when eva- 

 porated, gives a viscous amber-colored substance, which partly dissolves in 

 water ; treated with sulphuric acid, it decomposes like a soap, giving sulphate 

 of soda and an acid heavier than water. This acid contains both azote and 

 phosphorus ; analysed, it afforded exactly the composition which one of us 

 obtained from the cerebral fat, called oleophosphoric acid. 



The phosphureted fat which exists in the muscles, is therefore identical 

 with that which is found so plentifully in the brain, and is produced, like the 

 latter, by the combination of soda and oleophosphoric acid. The substance 

 can now be said to be found in every part of the animal organization. We 

 have established that its proportion hi the muscular tissue increases with the 

 age of the animal, and it is as various as the different species of the verte- 

 brate animals. Fishes, such as the whiting, the dab, the flounder, have only 

 a very small proportion, while species having a compact body, with a strong 

 taste, generally difficult to digest, like the mackerel, herring, trout, and most 

 of all, salmon, have a large quantity. It is this phosphuretted substance 

 which, by decomposing incompletely through the action of heat, gives to 

 broiled fish its characteristic smell. 



While studying this substance in the muscles of fish, we have been natu- 

 rally led to examine the red matter which colors the muscles of salmon, that 

 which, in trout and some other fish, produces the " saumonage" This remark- 

 able change of color is partly dependent on the phenomenon of reproduction. 

 The salmon, for instance, is red skinned all the year, but its muscles become 

 perceptibly paler at the time of spawning. This discoloration is still more 

 distinct in trout, for when they spawn the skin becomes quite white. While 

 the spawning does not occur at the same tune, the female " salmons" itself a 



