THE MICROSCOPE. 41 



below the average it should be diluted with water until it 

 reaches that point ; if the quantity be in excess of this aver- 

 age then it should be evaporated to that point. After pro- 

 ceeding thus, if the urine has a specific gravity over 1030, an 

 excess of urea may be the cause. To test for this, place 

 enough of the urine in a test-tube to fill it an inch in depth; 

 add to this one-third its bulk of pure niiric acid, and set in 

 a cool place, or in cold water, better always in water near the 

 freezing point. If crystals of nitrate of urea form in a few 

 moments then an excess of urea is present. Nitrate of urea 

 crystals are colorless, fiat, rhombic or hexagonal plates, closely 

 united to one another. 



To test for a deficiency of urea, take some of the urine, 

 of normal quantity, and reduce it to one-half its bulk by slow 

 evaporation; when cool add nitric acid as given above, and 

 set in cool water. If no crystals of nitrate of urea form in 

 five minutes then the normal amount is not present. This is 

 a very simple method, is easily applied, and approximates the 

 true results. 



We quote the following from the April number of The Micro- 

 scope: " The books have been balanced and Vol. I. of The Micro- 

 scope has closed. The experience of the past year has been of 

 great value to us, and we propose to give our readers the benefit 

 of it, by offering to them a much better journal. The unexpected 

 financial success of the enterprise proves that there was a demand 

 for a practical help of this kind. Therefore we say to all our 

 friends, give us your aid for another year — by getting your friends 

 to subscribe and by contributing practical articles to our columns." 

 The Microscope is worthy of the encouragement and support, not 

 only of those interested in its immediate object, but of those desir- 

 ous of aiding an attempt to materially benefit the University. May 

 it have many birthdays of financial and well merited success. — The 

 Chronicle. 



