Who demonstrated the concept of hydroponics for the first time?

Options

A. Joseph Priestly
B. Julius Von Sachs
C. Dalton
D. Calvin

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the individual who first demonstrated the concept of hydroponics. Hydroponics refers to a method of growing plants without soil, using a nutrient-rich solution instead.

2. **Identifying the Options**: The options provided are:
- A) Joseph Priestly
- B) Julius von Sasch
- C) Dalton
- D) Kelvin

3. **Researching Hydroponics**: Hydroponics is a technique that allows plants to grow in a water-based, nutrient-rich solution. It eliminates the need for soil, which is a significant aspect of this growing method.

4. **Historical Context**: The concept of hydroponics was first introduced in the 19th century. It is important to identify which of the listed individuals contributed to this concept.

5. **Finding the Correct Answer**: After reviewing the options and their contributions to the field of botany and agriculture, it is established that Julius von Sasch was the first to demonstrate the concept of hydroponics in 1860.

6. **Conclusion**: Therefore, the correct answer to the question is **B) Julius von Sasch**.