PROTECTIVE INOCULATIONS. 299 



" 1. The cholera vaccine is nothing more than a pure culture, in bouillon, 

 of the comma bacillus. Its easy and long preservation (four to five days) 

 allows of its transportability to great distances, taking care always to keep 

 the flask which contains the material upright. 



" 2. Heat and cold do not interfere with its preservation if the vaccine is 

 to be used in a short time. It should not, however, be kept out of doors dur- 

 ing the warm season. 



"3. The vaccine should be kept in flasks of the model of Ferraii, with a 

 flat bottom and a short neck. The stopper, which is of rubber, fits perfectly, 

 and is penetrated by two glass tubes. One, straight and short, which does not 

 extend below the inferior surface of the stopper, and which does not project 

 above more than some two centimetres, is plugged with a small quantity of 

 sterilized cotton and a superficial covering of wax. The other glass tube is 

 longer, and extends on the lower side as far as the bottom of the flask, while 

 its superior end is curved, and terminates in a capillary extremit3 r , the tip of 

 which is closed with wax. 



"4. When the vaccine is to be used it is necessary to make two principal 

 preparations for the operation. A small syringe for the hypodermic injection, 

 and a small vessel into which it is necessary to empty the fluid from the flask, 

 are required. The syringe should have metallic pistons and mountings, 

 without mastic of any kind and without rubber. Its capacity should be one 

 cubic centimetre, its needle thicker and shorter than that of ordinary use. 

 Before beginning the vaccination the syringe must be filled two or three 

 times with boiling water, which is aspirated and expelled through the needle. 

 This is called sterilizing the instrument, and by this means the extraneous 

 -mis are destroyed which might be contained in it, in order to avoid the 

 production of phlegmons and abscesses. The trouble in taking this precaution 

 will be little. Acting thus, one may perform thousands of injections without 

 fear of any accident. It is suggested that it is a bad custom to pass the nee- 

 dle through a flame in order to sterilize it, because this mode of procedure 

 draws the temper. Another precaution that must be taken relates to the 

 examination of the syringe before using it, in order to be well assured that the 

 piston acts perfectly and that not a single drop of the liquid escapes by a leak 

 in the cannula. This latter defect is sufficient to reject the instrument. If the 

 syringe aspires air because the leather washer, which is placed at the end of 

 the glass tube in order to facilitate its adaptation, is dry, or the piston is in the 

 same condition, it is necessary to delay a little while in order to take the 

 syringe apart and soak it in warm water. It is convenient to keep several 

 syringes for use, with a sufficient number of needles, when many inocula- 

 tions are to be performed. 



"5. The small receptacle into which the vaccine is poured in order that 

 the syringe may be filled readily is a capsule, a cup, or some similar vessel. 

 Before use, it should be washed and dried with extreme care, and imme- 

 diately before using passed through an alcohol or Bunsen flame, in order to 

 sterilize it. 



"6. All these preparations having been made, the drop of wax which 

 closes the capillary extremity of the long tube of the flask is removed, and at 

 the same time also the wax covering of the cotton stopper of the short tube, 

 but by no means must this cotton stopper be removed ; a rubber tube, or the 

 extremity of a small Richardson spray apparatus, is adjusted to the short 

 tube. The capillary extremity of the long tube is now slightly warmed in 

 order to soften somewhat the wax which may have been drawn into its 

 lumen by capillarity, and air is forced into the flask, either by blowing into 

 the rubber tube or by working the Richardson atomizer ; the air injected by 

 pressure upon the vaccine fluid forces the latter out through the long tube 

 with the capillary extremity, and it is collected in the cup or small sterilized 

 vessel. This latter is then covered with white paper, which has been 

 scorched in the flame, or with a sterilized glass plate ; as often as the syringe 

 is filled this cover will be removed and again immediately afterward replaced. 



