The relations of the diseases of animals to those of man.
- International Congress of Hygiene and Demography
- Date:
- 1892
Licence: Public Domain Mark
Credit: The relations of the diseases of animals to those of man. Source: Wellcome Collection.
Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.
243/260 page 243
![and remoying the crust is to use nothing which has been in contact with the ground or the air, and the necessity of using a clamp is to keep the lymph bloodless and to facilitate work. Vaccine lymph consists of two distinct parts, ciz., a fluid and a solid portion ; some calves yield mostly fluid lymph, others yield a com- paratively dry solid lym])!!, and in a third class the solid and fluid is equally distributed. Tlie fluid lymph is the serum of the blood, the solid is the tissue of the pock; both are very virulent. The first material from a vesicle is a yellow fluid, sometimes blood stained. After this is removed with a collecting spatula the next thing taken is tlie solid pock tissue ; this is completely scraped away, and by this time the clamp will require re-tightening; the next to appear is a thin, water}', colourless fluid, more like the lymph from the human arm, it exudes from the lymphatics, and I have proved it to be virulent. It is sometimes in great abundance. My own prejudice is in favour of the solid jjock tissue, as it is easier to keep aseptic, and, I think, retains its virulence longer. By means, then, of the collecting spatula, the whole vesicle is robbed bf its fluid and solid lymph, and placed in an agate mortar. Each vesicle is treated in the same way, being undamped after it is emptied. The crusts and silver areola belonging to each vesicle are kept separate for the vaccination of the next calf. The whole of the lymph, which may now weigh 11 grammes, is carefully and in small portions at a time ground up in an agate mortar to a fine emulsion; by this means the fluid and solid material is intimately mixed, and anything like portions of skin can be readily removed, as they impart a lumpy feeling to the j)estle which renders their detection easy and simple. After the whole lymph has been treated in this way a preserving agent is added; the best for the purpose is pure glycerine, the amount added depends on circumstances, but it is generally about equal to the bulk of lymph; the most thorough incor- poration of this mixture now takes place, and it is then placed in tinted tubes 1| inches long by ^ inch diameter, corks are inserted, and the whole sealed by dipping carefully in melted paratfin; this is now kept as stock, and protected from the light and heat. When small quantities of lymph are required, say for 10 to 25 people, the necessary amount is placed between squares of glass, plain or hollow, and the edges of these are dipped in melted parafiin and so sealed; this is a rapid and most convenient method of issuing lymph, and gives the operator the least trouble. The glasses are protected from light by being folded in tinfoil. When lymph for 100 persons is required, one of the tinted tubes above described is sent, as each holds sufficient for 100 vaccinations. Other methods of preserving and issuing lymph may be adopted, such, for example, as ivory points and capillary tubes, but I can say little for these, for the reason that the ivory point is wasteful, and some time is occupied in dissolving the lymph; moreover, the dried lymph does not maintain its ■\'itality for much more than two months, and in Q 2](https://iiif.wellcomecollection.org/image/b28045452_0245.jp2/full/800%2C/0/default.jpg)
