IHE ALUMNI JOURNAL. 



103 



Yet on examining samples of it under 

 circumstances which would surely have 

 revealed the presence of septic matter, 

 the results were negative. Nevertheless 

 it is now deemed advisable to use the ad- 

 ditional precaution to subject the catgut 

 to a preliminary sterilization, by boiling 

 it with enough alcohol of 94% to keep it 

 covered. This is done in a large wide- 

 mouthed Erlenmeyer flask, to the neck 

 of which is fitted an upright Allihn's 

 glass condenser (the condensing tube of 

 which has a number of bulb-like expan- 

 sions), whereby loss of alcohol is avoided. 

 The flask is set upon a steam-bath, and 

 the boiling kept up for one hour. The 

 strings are then taken out and immediately 

 transferred to the biniodized chloroform 

 in which they are left until wanted. 

 When they are taken out for use, they 

 are placed for a minute or so between 

 folds of sterilized gauze, to allow the 

 chloroform to evaporate. They will now 

 be found to be beautifully clean and more 

 or less bleached, and to have lost none 

 of their strength. Some surgeons prefer 

 the method mentioned above, under No. 

 I , which involves a previous maceration 

 in oil of juniper. In fact, the raw gut 

 is put into this oil and kept therein un- 

 til it is to be treated with boiling alco- 

 hol. The oil of juniper acts as a solvent 

 of the fatty matters, and therefore 

 may be regarded as an auxiliary to the 

 chloroform. But it is not necessary, and 

 may be omitted. 



The biniodized chloroform or "Chloro- 

 form with Biniodide," as it is usually 

 called, is prepared by adding 35 grains of 

 biniodide of mercury (free from lumps) 

 to 5 pounds of pure chloroform contained 

 in a flask provided with an upright 

 condenser, and boiling until the 

 biniodide is dissolved, which requires 

 about half an hour. The solution is 

 then transferred to bottles which 

 must be well stoppered. This solution 



is of the strength of i in 1000, and at the 

 ordinary indoor temperature is permanent. 

 When exposed to a temperature of about 

 60° F. or less, some of the biniodide will 

 separate in beautiful red crystals, but the 

 amount is never large, unless the liquid 

 is exposed to great cold. This biniodized 

 solution is at the same time a very deli- 

 cate reagent for the presence of chlorine 

 compounds existing as contaminations in 

 the chloroform. Any one of these com- 

 pounds which contain chlorine in looser 

 combination will set free enough iodine 

 to impart to the solution a pinkish or 

 pink tint. The depth of this color which 

 is characteristic for a solution of iodine in 

 chloroform, is in direct proportion to 

 the amount of contaminating chlorine 

 compounds present. Sometimes the tint 

 is developed at an early stage, during the 

 boiling of the chloroform with the binio- 

 dide. Again, it may make its appear- 

 ance gradually. It is not believed that 

 the presence of these contaminating 

 bodies have any deleterious influence 

 upon catgut which might be treated with 

 the solution, but the writer has preferred, 

 whenever the pink color revealed itself, 

 to make another use of the solution, 

 namely to recover the chloroform by dis- 

 tillation and to set it aside for use in 

 chloroform liniment or for other external 

 or coarser purposes. 



New York, April 12, 1896. 



THE DETERMINATION OF CAFFEINE 

 IN TEA. 



BY E. H. GANE, Ph. C. 



The exact determination of caffeine in 

 tea leaves is attended with great difiSculty. 

 Numerous processes have been devised, 

 but as will be seen later, most of these 

 have been based on inadequate informa- 

 tion, and are valueless for the purposes 

 intended. The process hitherto almost 



