44 GALLUS SONNERATI. 



perversely promoted in our public schools. In China the rage for 

 cock-fighting is still more prevalent than in this country ; and, hi 

 Sumatra, a man will hazard, not only his property, but his wife 

 and children, on a favorite bird." 



The domestic hen breeds more freely in warm than in col(l 

 climates. In this country and in France, if properly fed and 

 accommodated with cold water, gravel, and a warm situation, shtj 

 generally lays two eggs in the course of three days, and continue^ 

 to do so upwards of ten months. In the more northerly climates, 

 as in Greenland and Siberia, where they are kept as rarities, thc3 

 species do not breed. For much valuable information on the most 

 approved modes of managing domestic poultry, the reader may con- 

 sult the above-mentioned work of M. Temminck,and Parmenticr'tj 

 excellent observations, under the article Coq, in the Nouueau Die- 

 tionnaire d'Histoire Naturelle. 



The egg consists of four distinct parts ; firstly, the calcareous in- 

 vestment or shell ; secondly, the investing membrane ; thirdly, the* 

 white or albumen ; and fourthly, the yolk. The first of these, thq 

 shell, or putamen of the older anatomists, is composed of tho 

 carbonates of lime and magnesia, phosphate of lime, and animal 

 matter. The investing membrane is albuminous, and possesses 

 no important qualities, but was once esteemed efficacious in ague. 

 The white, which consists of nearly pure albumen, is a viscid, 

 transparent, colourless liquid; inodorous, insipid, and particu- 

 larly distinguished by the property of coagulating when exposed 

 to a temperature of about 1G5° Farh., into a white, opaque, 

 tough, solid substance. Chlorine, iodine, alcohol, and many of 

 the acids, also cause its coagulation, especially the sulphuric, nitric, 

 and muriatic acids. The galvanic battery produces the same 

 effect ; and tannin, and several of the metallic salts, form insoluble 

 precipitates with it, as the nitrate of silver, nitro-muriates of gold 

 and tin, acetate of lead, and the bi-chloride of mercury, which is, 

 perhaps, the most delicate test of the presence of albumen in 

 animal fluids. Sulphuric acid has a very peculiar action on albu- 

 men. Dr. Hope, the able Professor of Chemistry in the Uni- 

 versity of Edinburgh, discovered, many years ago, that this acid 

 immediately coagulates albumen, like the other strong acids, when 



