Variolation consisted of

Options

A. Injecting viriolous matter
B. Injecting heat-killed a viriolous matter
C. Scratching an area over a vein and pour small matter from a small pox pustule
D. Scratching vein and pouring viriolous matter into blood.

Answer

### Step-by-Step Solution:

1. **Understanding Variolation**:
- Variolation is a historical method used to provide immunity against smallpox, which is caused by the variola virus. It involves the deliberate exposure of a person to the virus in a controlled manner.

2. **Method of Variolation**:
- The process involves taking material from the pustules or scabs of an infected smallpox patient. This material contains the variola virus.

3. **Procedure**:
- The variolous matter (the material from the infected patient) is then introduced into a healthy individual. This is typically done by scratching the skin of the healthy person and applying the material directly onto the scratched area.

4. **Outcome**:
- After the procedure, the healthy individual may develop mild symptoms of smallpox, including the formation of pustules. However, this is a controlled exposure that allows the immune system to recognize and fight the virus.

5. **Recovery and Immunity**:
- After a few weeks, the individual usually recovers from these mild symptoms, and as a result, they develop immunity against future infections of smallpox.

6. **Correct Option**:
- Based on the explanation, the correct answer to the question "Variolation consisted of" is **Option C**: scratching an area over a vein and pouring a small amount of a smallpox pustule.