THE TECHNOLOGIST. [March I, 1865. 



344 ON CHEMISTRY APPLIED TO THE ARTS. 



of nutritive matter it yields to water under the most favourable circum- 

 stances. I repeat " the most favourable circumstances," for when meat 

 is placed in boiling water the 3 per cent, of albumen it contains is 

 coagulated, closing the vessels of the flesh, and preventing all further 

 exit of the fleshy fluids, and such should be the case when meat is in- 

 tended to be eaten as boiled meat and is properly cooked ; but when 

 the object in view is to extract the whole of the matter soluble in water, 

 as in the preparation of beef-tea, then the meat should be cut in small 

 pieces and brayed in a mortar with water, the whole then thrown into 

 clean linen and pressed. The juice of the flesh so obtained should then 

 be carried just to the boil, again passed through the strainer, and 

 after the addition of a little common salt will be ready for the patient. 

 Beef-tea even prepared by this process, which is certainly the best to 

 my knowledge, contains, as the table given shows, but a small cpiantity 

 of nutritive matter, there being only a little gelatine and a small propor- 

 tion of the other substances named above. Chevreul attributes the 

 odour of beef-tea and meat soups to osmazone, and Liebig to kreatine ; 

 in fact, Liebig considers kreatine to be one of the essential substances 

 characterising the aroma of various kinds of flesh. Liebig during his 

 researches on this substance succeeded in obtaining from — 



Fowl's flesh 3-21. of kreatine. 



Ox heart 1-37 „ 



Pigeon- 0-82 „ 



Beef 0-69 „ 



Further he observed, that the flesh of wild animals contained a much 

 larger proportion of kreatine than that of those which were confined : 

 for instance, that there was six times as much in the flesh of a wild fox 

 as in that of a tame one. Allow me to say a few words on the proper- 

 ties of this curious substance, which presents itself in the form of mode- 

 rately large white rectangular prisms, having a pearly lustre, soluble in 

 water, insoluble in alcohol. Although this substance is neutral, it is 

 converted when heated with hydrochloric acid into another solid crys- 

 tallized substance called " kreatinine," which possesses strong alkaline 

 properties. When kreatine, instead of being treated by an acid is acted 

 upon by baryta, it is converted into an acid compound called " inosinic 

 acid." Liebig ultimately succeeded in finding these substances, as well 

 as another called " sarcosine," in various animal secretions. I shall not 

 take up more of your time by discussing the chemical properties of these 

 substances, but merely state that they enable us to distinguish real soup 

 tablets from spurious ones. For this purpose a solution of the tablet in 

 cold water should be made, when, if genuine, it will give a precipitate 

 with chloride of zinc, whilst the spurious one, which contains gelatine 

 but no kreatine, will not do so. Another reaction is, that the pure 

 article will yield 85 per cent, of its weight to alcohol, whilst the imita- 

 tion will onlv vield about five. 



