Who is credited with study of external respiration for the first time

Options

A. Dutrochet
B. Pasteur
C. Cruickashank
D. Lavosier.

Answer

To answer the question "Who is credited with the study of external respiration for the first time?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand External Respiration**:
- External respiration refers to the process of gas exchange between the external environment and the bloodstream. It involves the intake of oxygen and the release of carbon dioxide.

2. **Identify Key Figures**:
- The question provides four options: Neutrochet, Pasteur, Cruikshank, and Lavoisier. We need to evaluate their contributions to the study of respiration.

3. **Evaluate Each Option**:
- **Dutrochet**: Known for his work on osmosis, not specifically on respiration.
- **Pasteur**: Renowned for his work in microbiology and vaccination, but not primarily for external respiration.
- **Cruikshank**: Primarily known as a book illustrator and not for contributions to respiration.
- **Lavoisier**: A French nobleman and a key figure in modern chemistry. He studied respiration and combustion, explaining it as a chemical reaction involving oxygen. He is often referred to as the father of modern chemistry and made significant contributions to our understanding of respiration.

4. **Conclusion**:
- Based on the evaluations, Antoine Lavoisier is credited with the study of external respiration for the first time. Therefore, the correct answer is option number 4: Lavoisier.

### Final Answer:
**Antoine Lavoisier is credited with the study of external respiration for the first time.**

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