204 The Microscope. 



cupied by the microtomes of American make — imitations of the 

 former, with such modifications and improvements as have b<'<-ii 

 suggested by the fertile and ingenious native mind. It appeared 

 to us that while the instruments of B. and L. worked in the main 

 well, their action was too stiff, too great effort being required to 

 move the knife. 



Bullock's microtome seems to combine many advantages ; 

 but for some reason the knife was unsteady, and as a conse- 

 quence could do work not much finer than the old-fashioned 

 hand instrument. It is greatly to be hoped that these faults 

 may be corrected during the coining year, so that at our next 

 meeting the American may stand abreast, or even excel, the for- 

 eign instrument. 



In this connection we may mention the ingenious freezing 

 microtome devised by Dr. F. O. Jacobs (table 21). This consists 

 of two copper cans, one within the other, and in the center of 

 the smaller a thick copper rod. The cans are fitted with tight 

 covers, both pierced by an opening for the rod, which is station- 

 ary, the table working up and down on a screw having 30 (?) 

 threads to the inch. The cans are filled with alternate layers of 

 pounded ice and salt, covered with water. Freezing begins al- 

 most immediately, and any tissue placed upon the rod is suffi- 

 ciently hard for cutting in from 15 to 20 minutes. Specimens 

 may be kept frozen by the instrument for four or more hours. 



Another demonstration to which attention should be called 

 was that of Prof. Burrill. In these days when bacteria, bacilli, 

 etc., play so important a role in the diseases to which flesh is 

 heir, it is interesting to know that vegetable life is also subject 

 to analogous conditions. That these vegetable germs are as cap- 

 able of cultivation as B. Tuberculosis or B. Anthracis, etc., was 

 ably shown by Mr. Burrill. 



The electric light so extensively used in all departments of 

 science has now been introduced in microscopy (table 26), but, 

 as now arranged, will scarcely meet the requirements of the ma- 

 jority of workers, as the expense, trouble, cumbersomeness of 

 the battery, etc., will hardly place its value as an illuminator 

 above that of the ordinary oil lamp. 



We might thus go on through the whole well planned and 

 interesting programme; but enough has already been said to 

 show the merits and uses of the working session. 



