THE MICROSCOPE. 



^0;cix":la3 gi'0cecjain0s. 



STATE MICROSCOPICAL SOCIETY, OF ILLINOIS. 



A MEETING of the State Microscopical Society of Illinois, was 

 held at the Academy of Science, No. 263 Wabash Ave., Fri- 

 day evening Feb. loth, 1882. 



The president Dr. Lester Curtis occupied the chair. After the 

 usual routine business Mr, E. B. Stuart read a paper entitled: 

 ''Notes on the lodo-Sulphate of Quinia." 



The speaker stated that some time ago it became desirable to 

 ascertain if a certain sample of muriate of morphia contained traces 

 of quinia, and on looking up the various methods which might be 

 used in making such a test he found no reference to the influence 

 of morphia on the iodo-sulphate test of therapath. As this test 

 had, for some time been a favorite with him, partly on account of 

 the certainty of the reaction. He first tried the reaction on a solu- 

 tion containing one part of quinia and nine of morphia. 



The morphia in this mixture did not prevent the formation of 

 the iodo-sulphate of quinia, nor did it have any effect when the 

 morphia was in the proportion of 1000 to i of quinia, and he thought 

 that in this test the morphia was entirely indifferent. 



The mode of performing this test, he stated was to dissolve the 

 salt in dilute alcohol by the use of sulphuric acid which is essential 

 to the reaction, and the solution warmed to about 100° F. Very dilute 

 tincture of iodine is then added, drop by drop, with constant agita- 

 tion. When a sufficient, or equivalent, quantity of iodine has been 

 added the precipitate suddenly appears and quickly subsides. 



In a mixture of the four principal cinchona alkaloids, the 

 quinia is first separated, then the cinchonidia, which is followed in 

 turn by thfe quinidia, and finally by the cinchonia. The latter reac- 

 tion takes place very slowly, however, and only in tolerably concen- 

 trated solutions. 



The separation of cinchonidia from quinia by this method is 

 far from complete, and unless present in large proportion, all the 

 cinchonidia is likely to be precipitated along with the quinia. On 

 recrystallizing from alcohol, however, the two salts separate and 

 can be distinguished by the microscope, although not very readily. 



