20 Dr. Golding Bird's Experimental Researches 



dryness in a glass capsule, yielded numerous delicate feathers 

 of hydrochlorate of ammonia. To obviate any source of fal- 

 lacy in this experiment, some of the same specimen of diluted 

 hydrochloric acid was evaporated to dryness ; but scarcely the 

 minutest traces of residue were visible even with the aid of a 

 lens. By simple distillation without admixture, mucus (as 

 stated by Dr. Pearson) does not yield the smallest trace of 

 ammonia ; hence we may very safely conclude, that although 

 mucus does not contain free ammonia, yet it contains a salt of 

 that base, most probably the chloride, (muriate of ammonia) 

 a salt which the ingenious researches of Raspail* have proved 

 to be almost universally present in animal fluids. 



8. Some fresh saliva, obtained without the use of any che- 

 mical stimuli, was mixed with an equal bulk of water, and 

 after violent agitation filtered ; this fluid was quite limpid, but 

 by exposure to the atmosphere in an imperfectly closed jar 

 during forty-eight hours, an opacity occurred precisely as in the 

 case of mucus (2), the substance deposited not being soluble 

 in nitric acid : the same thing occurred by exposure to an at- 

 mosphere of hydrogen gas. Some of this limpid dilute saliva 

 was exposed to heat in a glass tube ; no coagulation occurred : 

 but by protracted ebullition in a glass basin numerous flocculi 

 were deposited ; these flocculi could not be distinguished from 

 coagulated albumen by their behaviour towards reagents. 



9. Some fresh human saliva was filtered, and exposed in a 

 glass cup by means of copper wires to a current of electricity 

 from a battery of six pairs of plates two inches square, excited 

 by weak brine in the manner described in my last communi- 

 cation on this subject (18) : coagulation ensued in a few seconds 

 around the positive electrode; the coagulated mass adhered to 

 the wire, and acquired a green tint from the oxidation of the 

 copper electrode. Another portion of saliva was submitted 

 to the electrolytic action of an electric current, in two cups 

 connected by moistened cotton : coagulation very soon took 

 place at the same electrode as in the last described experi- 

 ment. 



10. Mucus diluted with water and filtered, presented the 

 same appearances when acted on by a voltaic current as saliva, 

 coagulation constantly taking place, and at the positive 

 electrode. 



11. When the coagulated substance separated by electric 

 action (9 and 10) from mucus or saliva was examined chemi- 

 cally, in no single feature was it found to differ from ordinary 

 coagulated albumen: in its solubility in acetic acid, alkalies, &c., 

 not the slightest discrepancy could be detected. 



• Nouveau Systlvie de Chimie Organique, pp. 195, 346, &c* 



