340 



Journal of Applied Microscopy. 



silver nitrate, and to bottle /, holding merely water. They do not employ pyro- 

 gallic acid for purification. Evolution of the gas can be controlled by a pinch- 

 cock, either at / or at /. As soon as 

 the desired amount of hydrogen has 

 passed, closure of the pinch-cock, or 

 stop-cock, at / or y", causes the hydrogen 

 in k to be developed under pressure. 

 This pressure soon forces back through 

 the tubes c and e all the sulphuric acid 

 and water, and the zinc is thus left dry 

 until the apparatus is again wanted. 

 Tube d\% simply for the inlet of air when 

 the acid mixture is pumped out, and 

 the exit of the same air when the 

 original contents come back. 

 This apparatus is so much cheaper than Kipp's, and is so much easier kept 

 in permanent operation, that it at once recommends itself. 



Again, this apparatus can easily be made by any one, and that cannot be 

 said of Kipp's. For instance, the Wolff bottles are not necessary. Two wide- 

 mouthed bottles would answer, through the cork of one of which three glass 

 tubes could be passed, and of the other two. Neither is the water pump neces- 

 sary. By blowing into a rubber tube connected with c/, or, better still, attaching 

 a bicycle pump to it, one could force the contents of bottle /into bottle /-. ;// 

 is a small piece of rubber tubing seized by a pinch-cock, ;/, and as this is the 

 only piece of rubber in the whole apparatus exposed to the acid mixture, but 

 little in the way of repairs is ever needed. 



This form of apparatus, of course, will do just as well for the evolution of 

 sulphuretted hydrogen as for the purpose just described. 



Ernest B. Sangree, M. D. 



Vanderbilt University, Nashville, Tennessee. 



BOOK NOTICES. 



Morell, Harry, M. D. C. M., F. R. M. S. Trinity ^his is a laboratory note-book for 



University, Toronto, Ont. Records of Uri- systematically recording the results of 



nary Examinations. J. S. Burr & Co., . ..... , 



Hanford, Conn. urmary analysis. Provision is made 



for one hundred records in duplicate, 

 one sheet being detachable, the other remaining in the book. The record 

 provides for notation as to physical characters and for physiological and 

 pathological constituents in solution, and also the results of microscopical 

 examination, with a special paragraph for bacteriological record. The results 

 of centrifugal analysis may also be recorded in connection with other tests. The 

 author says : " One examination of the urine is rarely a criterion in making a 

 diagnosis of any disease. The physician can at once see by looking back whether 

 the albumen or sugar in a certain case is increasing or diminishing ; or by 

 comparison of examinations he can make a more accurate determination of the 



