56 DEPARTMENT OP AGRICULTURE. 



gelatinous scrum, which is fluid so long as the lungs are hot, and is not readily contami 

 nated by other inflammatory products and blood. When a large portion of lung has been, 

 so far consolidated as to present an almost uniform dark red or purplish color, it should be 

 discarded, and especially in cases where a piece of the organ has become gangrenous and 

 detached, or where liquid in the cavity of the chest and around the lungs is decidedly 

 fetid. Microscopic examination will indicate, by the presence of movable rods and float 

 ing molecules, the putrefactive changes, and that should cause us to discard any such 

 source of virus. A clear pleural fluid is often very useful for preservation, but perhaps 

 greater reliance is to be placed on the exudation of a piece of lung in the first stage of 

 the malady. The lung is placed on a tolerably wide strainer, or bits of wood, over a clean, 

 stoneware, glass, or porcelain dish or bowl ; it is cut in various directions, and a stout piece 

 of cloth or flannel is placed over the whole to confine the heat and prevent dust falling on 

 the lung or liquid. It is better to place the dish or bowl over a warm water or sand bath 

 at 100, so as to prevent gelatinization. In a short time, according to the condition and 

 quantity of lung, a sufficient quantity of clear yellow-colored liquid is obtained. Some 

 times blood accidentally tinges the material, and this is not necessarily a disadvantage. 



The old plan of keeping pieces of lung to inoculate with, and bottling up anything 

 and everything to secure a fetid compound, to be kept for months, must be regarded 

 as the most certain means to insure accidents as the results of inoculation. 



Third. The preservation of the virus for periodic inoculations has certainly been a 

 desideratum. Had farmers and dairymen had the facilities for procuring material which 

 could be used with safety in their stock, they would long since have tried a method that, 

 even when badly followed, is beneficial to them. Dr. Sticker, of Cologne, has preserved 

 the virus in hermetically-closed tubes containing from one to two drachms. One of these 

 tubes is emptied into a small glass, and one to two parts of rain water added. This is not 

 desirable. A plan has occurred to me of utilizing the tubes referred to in the report of 

 Drs. Billings and Curtis, which I am sure will meet the requirements of the case. Tubes 

 about four inches in length, three-eighths of an inch in diameter, and tapering at either 

 end, are sealed at one end in a blow-pipe flame, and then heated throughout their length 

 to redness. The operation is concluded by closing the other end in the same way. The 

 air in the tube is rarefied, all germs of decay destroyed, and there is no difficulty in further 

 manipulations. When a proper quantity of liquid is obtained one point of the tube is 

 passed into it, the tip broken off, and the virus is sucked in to fill the vacuum. A spirit 

 lamp is held near the liquid, and the point of the tube transferred from this to the flame. 

 By the aid of a blow-pipe the sealing is effected, and thus protected the virus will keep 

 for months. The test for discarding tubes thus prepared is a microscopical one, and con 

 sists in the detection of bacteria or evidences of putrefaction in the liquid. 



Fourth. The inoculation of cattle is most safely practiced on the tip of the tail. All 

 parts that are loose, and from which any extensive exudation may spread over the con 

 nective tissue beneath the skin, must be avoided. The lips, dewlap, and root of the tail 

 have proved dangerous localities. When the operation is properly and delicately per 

 formed the tip of the ear is said to be safe, but, on the whole, the end of the tail is found, 

 after long experience, to be the best. 



Dairymen have frequently resorted to the plan of making an incision of an inch or 

 two in length, inserting in the part a piece of lung, and bandaging ; swelling, inflamma- 



