CHEMISTRY. , 507 



650 C, filter, wash with nitrate of ammonia sohition, dissolve on paper 

 with hot ammonia solution, and wash with same. Run in magnesia mix- 

 ture from a burette at the rate of one drop a second, stirring con- 

 stantly. Let stand several hours, filter, wash with ammonia solution, 

 dry, ignite to whiteness, and weigh. 



'{(].) Determination of ^Soluble Fhosphoric ^cid.— Weigh 2 grams, rub up 

 in a mortar with a soft, rubber- tipped pestle (grinding is avoided), digest 

 in 25 c. c. of cold water, decant clear liquid into a filteri)aper, filtering 

 into a 200 c. c. flask, add 25 c. c. of w^ater to residue, digest for several 

 minutes, and again decant. Repeat five or six times, and finally bring 

 all upon the fllter-paper and wash till flask is filled to the mark. Mix, 

 take 50 c. c, and estimate P2O5 as in (c). 



{€) Determination of Insoluble PJwsplioric AciW.— Wash the residue upon 

 the paper into a 200 c. c. flask with 100 c. c. citrate solution, cork the 

 flask, digest in a water-bath at constant temperature 05o C. (150° F.) 

 for thirty minutes, with frequent agitation. Filter the warm solution 

 quickly (by the aid of a filter-pump if convenient) and wash with cold 

 water.' Return paper and contents to the same 200 c. c. flask, add 50 

 c. c. nitric acid, boil for 15 minutes, and estimate the P2O5 as in (c). 



(/-) Determination of Reverted Phosphoric Acid.—Tha soluble -f insolu- 

 ble phosphoric acid subtracted from the total will give the reverted 

 phosphoric acid. 



Memoranda.— The uiolybdic solution is made, as usual, to contain 5 per 

 cent. M0O3, and GO c. c. are used to every 0.100 gram P,05. The mag- 

 "nesia mixture is made up as follows : 110 grams cryst. MgCl2, 300 grams 

 NH4CI, 400 c. c. cone, ammonia, 1,500 c. c. water; 10 c. c. are used to 

 every 0.100 gram P2O5. The citrate solution is made of specific gravity 

 1.09,^ carefully neutralized. The ammonia solution contains 1 part 

 strongest ammonia to 3 parts of water. The nitrate of ammonia so- 

 lution is a 10 per cent, solution, slightly acidified with nitric acid. {Am. 

 Chem. Journ., vi, 1.) 



ORGANIC. 



Nomenclature of Organic Compounds.— A& the prodigious number of 

 organic bodies rapidly augments, the difficulty of providing for them a 

 satisfactory system of terminology likewise increases. Prof. Adolf 

 Baeyer proposes certain changes and some novelties; he favors the 

 use of the letter B to express the benzene-ring, and of the letters Py to 

 indicate the pyridine-ring, employing them as in the following example : 



B-1, 4-dichloro-Py 1, 3-dioxychinoliue. 

 He also proposes to use the Greek letter a? to denote the first carbon 

 atom in case of the derivatives, this to be followed by a, /i, y, &c., as 

 u^uil To distinguish substitutions in the rings from those in the side 

 chains the autbor proposes to employ the syllable eso in the first m- 



