i62 THE MICROSCOPE. 



in water to which a little chloride of ammonium has been added. 

 Cystine is preserved either in glycerine jelly or in the naphtha and 

 ereasote solution. 



The urates and uric acid are preserved in the naphtha and 

 ereasote solution also. Crystals of uric acid show nicely when 

 mounted in Canada balsam. To mount them in balsam, they must 

 first be thoroughly washed with distilled water and then carefully 

 dried. They are dried the best under a bell jar over sulphuric acid. 

 When dry, a drop of oil of turpentine is added, and this is allowed 

 to nearly evaporate when a drop of Canada balsam is added and the 

 slide gently warmed. Care must be exercised here that the heat be 

 slight, otherwise the crystals will be cracked in every direction. 

 These crystals show very nicely when mounted in this way. Crystals 

 of oxalate of lime are best preserved in the naphtha and ereasote 

 solution. 



Many of the crystals obtained from urine are preserved the 

 best in a dry state. Such are urea, nitrate of urea, oxalate of urea, 

 creatine, creatinine, and many others. These crystals are 

 allowed to form upon the glass slide, when they are thoroughly 

 dried under a bell jar over sulphuric acid. A shallow ring 

 of white zinc can be placed around the crystals and the 

 cover applied and hermetically sealed. In the great majority of 

 cases the crystals obtained from urine are not preserved in their 

 mother liquid. 



T 



MICROCOCCI. 



BY J. M. ADAMS. 



HE micrococci, the smallest of the schigomycetes or splitting 

 cells, are among the very smallest of microscopic forms, and 

 are generally passed over by microscopists because so minute and 

 troublesome to examine. Being so near mere points, a correct 

 measurement is most perplexing, as they range from ^yj-yo- to 

 ^^\^ ^ of an inch in diameter, or only about the width of the 

 flagella of the larger bacteria, which many have never yet seen; 

 however, they are handled much more easily than minute monads, 

 as they are motionless. Some are oval, but most are round; nearly 

 all are dark colored, yet some are quite transparent, if not wholly 

 so, and may be often overlooked. They may be mistaken for 



