Step 1: Understanding the Concept:
The question asks to identify a specific landmark case by its popular name, the "Solicitor's Case". This case is famous for its discussion on whether certain professional establishments, like a solicitor's firm, fall under the definition of 'industry' as defined in the Industrial Disputes Act, 1947.
Step 2: Detailed Explanation:
The case of National Union of Commercial Employees v. Industrial Tribunal, Bombay, AIR 1962 SC 1080, is popularly known as the Solicitor's Case.
In this case, the Supreme Court had to decide whether the office of a solicitor (a lawyer) is an 'industry'. The court held that a solicitor's firm is not an industry because the services provided are based on the individual skill, knowledge, and intellectual capacity of the professional. It observed that the professional service is characterized by a direct personal relationship with the client and lacks the commercial or production-oriented nature of an 'industry'. The contribution of capital or labour is not the primary factor.
This judgment was later revisited and its scope was narrowed by the landmark ruling in \textit{Bangalore Water Supply and Sewerage Board v. A. Rajappa}, which gave a much wider interpretation to the term 'industry'.
Step 3: Final Answer:
The case popularly known as the Solicitor's Case is National Union of Commercial Employees v. Industrial Tribunal, Bombay.