/v .\ 1 M A L C 1:1 E M I IS T li 1 . 



fact, that we do not know the absolute num- 

 ber of the atoms of their elements, which 

 have united to form the compound atom. 



15. A formula for proteine is nothing 

 more than the nearest and most exact ex- 

 pression in equivalents, of Ine result of the 

 best analyses; it is a fact estabhsned so far, 

 free from doubt, and this alone is, for the 

 present, valuable to us. 



If we reflect, that from the albumen and 

 fibrine of the body all the other tissues are 

 derived, it is perfectly clear that this can 

 only occur in two ways. Either certain 

 elements have been added to, or removed 

 irorn, their constituent parts. 



If we now, for example, lock for an ana- 

 lytical expression of the composition of cel- 

 lular tissue, of the tissues yielding gelatine, 

 or tendons, of hair, of horn, &c., in which 

 the number of atoms of carbon is made in- 

 variably the same as in albumen and fibrine, 

 we can then see at the first glance, in what 

 way the proportion of the other elements 

 has been altered; but this includes all that 

 physiology requires in order to obtain an in- 

 sight into the true nature of the formative 

 and nutritive processes in the animal body. 



From the researches of Mulder and Sche- 

 rer we obtain the following empirical formulae. 



Composition of organic tissues. 

 Albumen . . . 

 Fibrine . . . 

 Caseine . . . 

 Gelatinous tissues, > _ 



Chondrine . . . C 48 N 6 H 40 O 

 Hair, horn. . 

 Arterial membrane 



The composition of these formulae shows, 

 that when proteine passes into chondrine, 

 (the substance of the cartilages of the ribs,) 

 the elements of water, with oxygen, have 

 been added to it; while in the formation of 

 the serous membranes, nitrogen also has 

 entered into combination. 



If we represent the formula of proteine, 

 C'WH^O 14 by Pr, then nitrogen, hydrogen, 

 and oxygen have been added to it in the 

 form of known compounds, and in the fol- 

 lowing proportions, in forming the gelatinous 

 tissues, hair, horn, arterial membrane, &c. 

 Proteine. Ammonia. Water. Oxygen. 

 Fibrine, Albumen Rr 

 Arterial Membrane Pr . +2HO. 

 Chondrine . . Pr . +4HO.4-2O. 

 Hair, horn . . Pr+ NH 8 . . + 3O. 

 Gelatinous tissues 2Pr-f3NH 3 -f HO.+7O. 



17. From this general statement it ap- 

 pears that all the tissues of the body contain, 

 for the same amount of carbon, more oxygen 

 than the constituents of blood. During their 

 formation, oxygen, either from the atmo- 

 sphere or from the elements of water, has 

 been added to the elements of prot^ne. In 



* The quantities of sulphur and phosphorus 

 here expressed by S and P are not equivalents, 

 but only give the relative proportions of these two 

 elements to each other, as found by analysis. 



hair and gelatinous membrane we observe, 

 farther, an excess of nitrogen and hydrogen, 

 and that in the proportions to form ammonia. 



Chemists are not yet agreed on the ques- 

 tion, in what manner the elements of sul- 

 phate of potash are arranged; it would 

 | therefore be going too far, were they to 

 I pronounce arterial membrane a hydrate of 

 proleine, chondrine a hydrated oxide of pro- 

 teine, and hair and membranes compounds 

 of ammonia with oxides of proteine. 



The above formula? express with preci- 

 sion the differences of composition in the 

 chief constituents of the animal body; they 

 show, that for the same amount of carbon 

 the proportion of the other elements varies, 

 and how much more oxygen or nitrogen 

 one compound contains than another. 



18. By means of these formulae we can 

 trace the production of the different com- 

 pounds from the constituents of blood ; but 

 the explanation of their production may 

 take two forms, and we have to decide 

 which of these comes nearest to the truth. 



For the same amount of carbon, mem- 

 branes and the tissues which yield gelatine 

 contain more nitrogen, oxygen, and hydro- 

 gen than proteine. It is conceivable that 

 they are formed from albumen by the addi- 

 tion of oxygen, of the elements of water, 

 and of those of ammonia, accompanied by 

 the separation of sulphur and phosphorus ; 

 at all events, their composition is entirely 

 different from that of the chief constituents 

 of blood. 



The action of caustic alkalies on the tis- 

 sues yielding gelatine shows distinctly that 

 they no longer contain proteine ; that sub- 

 stance cannot in any way be obtained from 

 them; and all the products formed by the 

 action of alkalies on them differ entirely 

 from those produced by the compounds o'i 

 proteine in the same circumstances. Whe- 

 ther proteine exist, ready formed, in fibrine. 

 albumen, and caseine, or not, it is certain 

 that their elements, under the influence of 

 the alkali, arrange themselves so as to forru 

 proteine; but this property is wanting in the 

 elements of the tissues which yield gelatine 



The other, and perhaps the more proba- 

 ble explanation of the production of these 

 tissues from proteine, is that which makes it 

 dependent on a separation of carbon. 



If we assume the nitrogen of proteine to 

 remain enure in the gelatinous tissue, then 

 the composition of the latter calculated on b 

 equivalents of nitrogen, would be repre- 

 sented by the formula, C^N^^O 14 . This 

 formula approaches most closely to the 

 analysis of Scherer, although it is not an 

 exact expression of his results. A formula 

 corresponding more perfectly to the analysis, 

 is C'WH^O 12 ; or calculated accordin to 

 Mulder's analysis, 



* The formula C^NsH^O 20 , adopted by Mu! 

 der, gives, when reduced to 100 parts, too little 

 nitrogen f> be considered an exact expression of 

 his analyses. 



