H2 



C H R MI S T R V. 



Competi- 

 tion. 



and published the reiulti of hi* experiments. The mar. 

 row on which his trials were made was obtained from 

 the thigh bone of an ox. 



Marrow, freed from its impurities, has a white colour 

 with a shade of blue; its taste is insipid and rather sweet- 

 ish. It softens by the heat of the hand, and melts when 

 heated to 113. When cooled slowly, it crystallizes in 

 Rphericles like olive oil. It burns with a flame like tal- 

 low. When distilled it gives lirst a transparent fluid yel- 

 lowish oil, accompanied by carbonic acid gas, water, 

 and heavy inflammable air. Afterwards there comes orer 

 a white solid oil, accompanied by a less copious evolu- 

 tion of gaseous bodies, and which does not become dark 

 coloured, as happens when tallow is distilled. This had 

 already been observed by Neumann. This solid oil has 

 a disagreeable smell, amounts to 0.8 of the marrow dis- 

 tilled, reddens vegetable blues, and when boiled in water 

 gives out a portion of scbacic acid, which Bcrzelius con- 

 siders as ben/oic acid. 



The empyreumatic oil combines readily with alkalies 

 and their carbonates. With the latter it forms a snow 

 white soap, insoluble in water, though it increases in 

 bulk when placed in contact with that liquid. It com- 

 bines also with the earths, and forms soaps likewise inso- 

 luble in water. 



The water which comes over during the distillation of 

 marrow is colourless, has a fetid and sour smell, and an 

 empyreumatic taste. It contains a little acetic acid, em- 

 pyreumatic oil, and probably benzoic acid ; but exhi- 

 bits no traces of ammonia. 



The gaseous products amount to one- tenth of the mar- 

 row distilled. They contain no sulphur nor phosphorus, 

 and consist of carbonic acid and heavy inflammable air, 

 which burns with a white flame, and seems to contain 

 oil in solution. 



The charry matter in the retort amounts to 0.05 of 

 the marrow distilled. It is dark brown, heavy, and bril- 

 liant. It is incinerated with difficulty, and leaves an ash 

 consisting of phosphate of lime, carbonate of lime, and 

 some soda. 



Marrow combines with alkalies and forms soap. Boil- 

 ing alcohol and ether dissolve a small portion of it, which 

 precipitates again as soon as the solution cools. 



Marrow, from the thigh bone of an ox, was found, 

 by Berzelius, to be composed of the following sub- 

 stances : 



Pure marrow 0.96 



Skins and blood-vessels 0.01 



Albumen 



Gelatine 



Extractive ^ 0.03 



Peculiar matter 



Water 



1.00 



From the preceding detail, it appears, that pure mar- 

 row is a species of fixed oil, possessing peculiar pro- 

 perties, and approaching somewhat to butter ia its ua- 

 ture. 



SECT. VIII. Of Hair and Feathers. 



These substances cover different parts of animals, and 

 are obviously intended by nature to protect them from 

 the cold. For this, their softness and pliability, and the 

 ilowness with which they conduct heat, render them 

 peculiarly proper. 



1. Hair is usually distinguished into various kinds, 



according to ill tizt and appearance. The strongest and Chemical 

 stiffest of all it called >t tins kind is the hair on 



the backs of hops. \V1 :.ably fine, soft, and ' 



pliable, it is called wool ; ami the finest of all in known ^J_ ^ 

 by the name of down. But all these varieties resemble 

 one another very closely in their composition. 



Vauquelin j puMished a curious set of expe- 



riments on the analysis of human hair of various colours. 

 Though hair is insoluble in boiling water, he obtained a 

 solution by raising the temperature of the liquid in a 

 Papin's digester. If the heat thus produced was too 

 great, the hair was decomposed, and ammonia, carbonic 

 acid, and an empyreumatic oil formed. Sulphureted 

 hydrogen is always evolved, and its quantity increases 

 with the heat. When hair is thus dissolved in water 

 heated above the boiling point, the solution contains a 

 kind of bituminous oil, which is deposited very slowly. 

 This oil was black when the hair'dissolvcd was black, 

 but yellowish red when red hair was employed. 



\Vhcn the solution is filtered to get rid of this oil, tbe 

 liquid which passes through is nearly colourless. Copi- 

 ous precipitates are formed in it by the infusion of nut- 

 galls and oxymuriatic acid. Silver is blackened by it, 

 and acetate of lead precipitated brown. Acids render 

 it turbid, but the precipitate is re-dissolved, by adding 

 these liquids in excess. Though very much concentra- 

 ted by evaporation, it does not concrete into a jelly. 



Water containing only four per cent, of potash dis- 

 solves hair, while hydrosulphuret of ammonia is evolved. 

 If the hair be black, a thick dark-coloured oil, with 

 some sulphur and iron, remains undissolved ; if the hair 

 be red, there remains a yellow oil, with some sulphur 

 and an atom or two of iron. When acids are dropt in- 

 to this solution, they throw down a white matter solu- 

 ble in an excess of acid. 



Sulphuric and muriatic acids become red when first 

 poured on hair, and gradually dissolve it. Nitric acid 

 turns hair yellow and dissolves it, while an oil separates, 

 which is red or black according to the colour of the 

 hair dissolved. The solution yields a great deal of oxa- 

 lic acid, and contains, besides, bitter principle, iron, and 

 sulphuric acid. Oxymuriatic acid first whitens hair, and 

 then reduces it to a substance of the consistence of tur- 

 pentine, and partly soluble in alcohol. 



When alcohol is digested on black hair, it extracts 

 from it two kinds of oil. The first, which is white, 

 subside!) in white shining scales as the liquor ccoh ; the 

 second is obtained by evaporating the alcohol. It has a 

 greyish green colour, and at last becomes solid. From 

 red hair alcohol likewise separates two oils ; the first 

 white as from black hair, and the other as red as blood. 

 When the red hair is deprived of this oil, it becomes of 

 a chesnut colour. Hence its red colour is obviously ow- 

 ing to the red oil. 



When hair is incinerated, it yields iron and manga- 

 nese, phosphate, sulphate, and carbonate of lime, mu- 

 riate of soda, and a considerable portion of silica. The 

 ashes of red hair contain less iron and manganese : those 

 of white hair still less ; but in them we find magnesia, 

 which is wanting in the other varieties of hair. The 

 ashes of hair do not exceed 0.015 of the hair. 



From the preceding experiments of Vauquelin, we fomposi- 

 learn that black hair is composed of the nine following lion of 

 substances: black tata 



1. An animal matter, constituting the greatest part. 



2. A white solid oil, small in quantity. 



3. A greyish green oil, more abundant. 



4. Iron ; tate unknown. 



