144 A:!yI^tAL FLUIDS* 



siflerably greater quantity than that indicated above, yet the 

 addition ol the sulphuric acid jModuced no visible effervescence. 

 I.tiink it must therefore rcniain undetermined, whether the al- 

 kali exist in the pure or carboHatcd slate. 

 Concerning The method of ascertaining the exact quantity of jelly in any 



say^separated' compound fluid is, upon the whole, more easy. Isinglass at- 

 and its qiuinti- fords US the means of obtaining jelly in a state of almost perfect 

 by tannin'.'"*^ purity ; by forming a solution of this substance, and an infusi- 

 on of galls of a known strength, by adding them to each other 

 until they are neutralized j and collecting the precipitate, we 

 can ascertain the respective proportions necessary to produce 

 the neutral compound. As the precipitate formed in this case 

 subsides slowly, it is more convenient, after the mixture of the 

 jelly and the galls, to filter the compound, and to add a little 

 of the filtered fluid to fresh solutions of jelly and galls respec- 

 tively ; from observing iawhich of the solutions a precipitate is 

 produced, we are enabled to determine which ingredient exists 

 •in excess, and to correct the deficiency in a subsequent experi- 

 ment ; this process must be repeated until the filtered fluid pro- 

 duces no precipitate with cither of the reagents. By proceed- 

 ing in this mtmner I am led to conclude, that the compound 

 formed by the union of jelly and tannin consists of somewhat 

 less than two parts of tannin to three of jelly ; as we always 

 have it in our power to ascertain the quantity of tan that we em- 

 ploy,, we may, by an easy calculation, deduce the amount of 

 the jell}' in any fluid under examination. 

 The proportion J have not vet iieen able to fall upon a method for directly 



OfjnWCUSnOt ,,-•/ r in-i- 



easily deter- determming the proportion ot mucus ni a compound nuid, m 



njined. consequence of the facility with which goulard decomposes the 



different ingredients, both animal and saline, which are always 



•to be suspectgd in those substances that contain muGus, even in 



a state the nearest approaching to purity. jMuriate of soda is> 



I believe, always present wherever we have mucus ; and the 



: goulard, which so readily and completely precipitates the 



: mucus, likewise decomposes the common salt. The nitro-mu- 



riate and the muriate of tin, and the nitro-muriate of gold, ajl 



- cause u considerable. precipitation in a solution of salvia ; but 



'■-tlie supernatant fluid remains opake, as if it still contaiBed some 



animal matter; and, inconsequence of the muriatic acid 



- ■ which enters into' -the composition of these salts, we are not able 



after- 



