Journal of Applied Microscopy. 



157 



cut in one section. They are then fixed 

 to a cover-glass of suitable size by 

 means of the water-albumen method 

 suggested by the writer. After the re- 

 moval of the paraffin the sections may 

 be stained at pleasure. 



The applicability of this method may 

 be shown by a number of examples. Por- 

 tions showing typical regions of the sev- 

 eral parts of the alimentary canal, all 

 hardened after the same method, are di- 

 vided in small pieces suitable for em- 

 bedding, the following pieces being se- 

 lected: oesophagus, junction of oesopha- 

 gus and cardiac end of stomach, cardiac 

 and pyloric region of stomach, junction 

 of pyloric end of stomach with small 

 intestine showing Brunner's glands, 

 small intestine, small intestine with 

 solitary lymph follicle, and large intes- 

 tine. These pieces are embedded in two 

 paraffin blocks in the order named, cut 

 and fixed to two cover-glasses, one inch 

 by three-quarter inch, stained in haema- 

 toxylin and eosine or haematoxylin and 

 Van Gieson's acid fuchsin-picric acid 

 mixture, and mounted on one slide. In 

 such a preparation the student can read- 

 ily pass from one section to another, 

 make comparisons, and will, I believe, 

 form a clearer idea of the difference in 

 the structure of the several regions of 

 the alimentary canal, than he would by 

 studying eight or ten different slides. 

 Much time is saved the instructor in 

 preparing material, and the student in 

 mounting sections. Again, pieces taken 

 from the various glands — serous and 

 mucous salivary glands, pancreas, liver, 

 kidney, thyroid, etc., may b^i mounted in 

 one block and treated in the same way. 

 The various adenoid tissues — simple fol- 

 licle, lymph gland, thymus, and spleen 

 may be similarly treated, or, to give an- 

 other example, voluntary, heart, and in- 

 voluntary muscle tissue, may in like 

 manner be stained and mounted under 

 one cover-glass. I have found that such 

 preparations emphasize and fix the char- 

 acteristic features of the above named 

 tissues better than a series of separate 

 sections do. 



The applicability of this method has 

 not been tested in teaching classes in 

 pathological histology. I may venture 

 to suggest, however, that there also the 

 method may be of use. For instance, 

 pieces taken from tissues showing the 

 several types of carcinoma or sarcoma 

 may be treated after the above method. 

 Pieces taken from a collection showing 

 the various pathological conditions of the 

 kidney or liver or any other organ may be 

 blocked in as compact a form as possible 

 and similarly treated. 



The suggestions here offered may have 

 a much wider use in laboratories than 

 the writer is aware of. He has not ob- 



served them in laboratories with which 

 he is more or less familiar. 



G. Carl Huber. 

 Histological Laboratory, University of 

 Michigan. October 19, 1898. 



Laboratory Methods in Bacteriol- 

 ogy. 



Dr. F. G. Novy. 

 ^^1#— Examination of Bacteria. 



This and the following papers are 

 written at the request of the editor, and 

 are primarily intended for the busy prac- 

 titioner who has not the time to take the 

 regular course in a well equipped labo- 

 ratory. Although he cannot spend one 

 or two months away from his patients, 

 yet one or two hours a day may be found 

 which, if properly used, will enable him 

 in a short time to acquire the necessary 

 knowledge aiid skill in identifying the 

 most important disease producing bac- 

 teria. Once acquired, this knowledge will 

 be found to be an invaluable aid in the 

 diagnosis of certain infectious diseases. 



Many, undoubtedly, are deterred from 

 entering upon such self-study because 

 they believe that such work can be done 

 only in a well equipped laboratory, and 

 that too great an expense would be in- 

 curred in providing one's own outfit. It is 

 the purpose of the writer to show that a 

 great deal of good work can be accom- 

 plished along this line at little expense. 

 The satisfaction of broadening one's hor- 

 izon of thought will amply repay the 

 time and expense involved. 



The first and most expensive piece of 

 apparatus necessary for work is a good 

 microscope. Every physician, without 

 exception, should have and be able to use 

 to advantage this instrument. The rapid 

 strides in scientific medicine have made 

 this a necessity. Fortunately, with the 

 increased demand for this means of in- 

 vestigation, the price has been lowered 

 so that a good microscope is within the 

 reach of every one. The beginner who 

 finds it necessary to economize will do 

 well to purchase an instrument with two 

 eyepieces and two objectives, the latter 

 being designated as two-thirds and one- 

 eighth-inch. Such an instrument can be 

 purchased for about $50.00. Later on, a 

 triple revolving nosepiece and a one- 

 twelfth^inch homogeneous oil-immersion 

 objective can be added. 



The necessary accessories are: 



A pair of forceps, 



A platinum wire. 



Three concave glass slides, 



Fifty glass slides, 



One-half ounce No. 1 cover-glasses, 

 three-fourths inch in diameter. 



One tube of Canada balsam. 



