SECT. 3] 



AND EIGHTEENTH CENTURIES 



225 



EXCERPTS FROM J. F. JOHN'S CHEMISCHE TABELLEN OF 1814 {cent.) 

 Substance or liquid 



Composition 



investigated 

 Eggs (domestic hen) 

 Shell 



Investigator Date 



Shell-membranes 



A fine earth and a gelatinous material 

 True lime, containing perhaps phos- 

 phoric acid 

 \ oz. of pulverised clean shell, di- 

 gested with spirits of wine, gave i \ 

 grains of an extract which smelt and 

 tasted rancid. The same amount of 

 shell gave i scruple of a yellow 

 watery extract which tasted salt 

 Carbonate and phosphate of lime, 

 traces of a jelly, which can be used 

 as gum. Phosphoric acid can be 

 had from the ash 

 Carbonate and phosphate of lime, 

 bitter earth and iron, a jelly which 

 can be used as gum 

 Carbonate of Hme 72 parts, phos- 

 phate of lime 2, jelly 3, water and 

 loss 23 

 Carbonate of lime 89-6 parts, phos- 

 phate of lime 5-7, animal substance 

 4-7, traces of sulphur. As a hen lays 

 130 eggs in six months and as an 

 egg weighs on an average 58-117 

 grams, 7486-226 grams of solid must 

 be used for egg-production in that 

 time, i.e. since the shells would 

 weigh 64-685 gm., 7333-793 gm., 

 14 pounds 15 ounces 7 gros 8 

 grains. The secretion of the lime is 

 probably accomplished by means 

 of the kidneys 

 Carbonate and phosphate of lime, 

 and jelly 

 Very much carbonate of lime, very 

 little phosphate. Traces of phos- 

 phate of iron, earthy carbonates, 

 rnuriates, albuminous and gela- 

 tinous substance to hold it together. 

 I cannot find any uric acid in it, as 

 Vauquelin says is there, nor is he 

 right in saying that the sulphur is 

 in the shell — it is in the membranes 

 only, and under the form of sul- 

 phuric acid 



Consist of an animal material 

 Have the properties of the fibrous 



part of blood 

 A jelly-like material, soluble in hot 



water 

 An animal substance with traces of 



phosphate of lime, carbonate of 



lime, muriates, and a sulphurous 



body 

 An albuminous substance containing 



traces of sulphur and soluble in 



caustic potash 



Macquer 

 Leonhardi 



Neumann 



Berniard 



Hatchett 



1 781 



1780 



1800 



Merat-Gaillot — 



Vauquelin 1 799 



Fourcroy 

 John 



1811 



Macquer 

 Jordan 



Fourcroy 



John 



178: 



1811 



Vauquelin — 



15 



