The Microscope. 157 



HEPATIC CELLULE. 



In choosing an animal upon which to carry out my histo- 

 logical work, after trying quite a number of different kinds of 

 vertebrates, I settled at length upon the domestic rat as the best, 

 and for these reasons : It is a small animal, easily obtained in 

 almost any numbers, and sacrificed almost as easily as frogs. 

 The hepatic cellules of the rat are extremely neat and clear, 

 and is the rarest of things to find them charged with the fatty 

 granulations sufficient to impede observation. Let us then take 

 a rat, an ordinary rat, mus decumanus, and cut his head off. 

 Taking off a bit of his liver, say a tenth of an inch in diameter, 

 we put it into one or two cubic centimeters (from 15 minims to 

 a half drachm) of a one per cent, solution of osmic acid and 

 leave it there from 12 to 24 hours. After washing thoroughly 

 in distilled water to get rid of the excess of osmic acid, we put 

 it on a glass slip, and covering it with a drop of water, proceed to 

 disintegrate it by tearing it with needles. Since the elements 

 have been fixed, this process is a comparatively easy one, and 

 by this means we obtain a vast number of hepatic cells beauti- 

 fully isolated, which can be mounted and examined at leisure. 

 — Cincinnati Med. News. 



NEWSPAPER SCIENCE. 



It would be difficult to crowd into one sentence more utter 

 and ridiculous nonsense than is to be found in the following 

 paragraph, which originally appeared in the " scientific " notes 

 of the New York Sun, and which is republished, without com- 

 ment, in a similar column of a prominent medical journal, whose 

 editor should know better : 



" A German chemist advertises that he will furnish Koch's 

 comma bacillus" — the supposed infective germ of cholera — 

 " ready mounted on slides for popular use in microscopes," As 

 there seems to be some foundation for Professor Koch's state- 

 ment that these germs, though harmless when dry, recover 

 their activity when moistened, the " popular " microscopist will 

 do well not to fool with these slides during this summer, lest 

 he might accidentally drop one of them into a pitcher of drink- 

 ing water." 



