import matplotlib.pyplot as plt
import pandas as pd

# Load the Iris dataset
iris = pd.read_csv('https://archive.ics.uci.edu/ml/machine-learning-databases/iris/iris.data', 
                    header=None, names=['sepal_length', 'sepal_width', 'petal_length', 'petal_width', 'class'])

# Define the size and color of the bubbles
size = iris['petal_length'] * 50 # scale up the values to make the bubbles more visible
color = iris['petal_width']

# Create a bubble chart with four dimensions
plt.scatter(iris['sepal_length'], iris['sepal_width'], s=size, c=color, cmap='viridis')

# Add axis labels and a title
plt.xlabel('Sepal Length')
plt.ylabel('Sepal Width')
plt.title('Bubble Chart of Iris Dataset')

plt.show()