Note 9.  Long-Term Assets

Intangible rights acquired

As of December 31, 2019, intangible rights acquired totaled zero. As of December 31, 2018, intangible rights acquired totaled $0.7 million, which were associated with the Company’s Logical Brokerage acquisition in March 2018. The Company made the decision, effective as of December 31, 2019 not to pursue its RiotX / Logical Brokerage business development plan. See Note 4.

Deposits on equipment

During December 2019, the Company purchased 1,000 next generation Bitmain S17 Pro Antminers from Bitmain for approximately $1.4 million. As of December 31, 2019, the Company has not yet received the miners and recorded the $1.4 million as a deposit on the accompanying consolidated balance sheet.

Patents

The Company’s intangible assets with finite lives consist of its patents pertaining to its legacy animal health business, which have been out-licensed. For all periods presented, all of the Company’s identifiable intangible assets were subject to amortization. The carrying amounts related to acquired intangible assets as of December 31, 2019 and 2018 were as follows (in thousands):

The following table represents the total estimated amortization of intangible assets for the five succeeding years and thereafter (in thousands):

The Company capitalizes legal costs and filing fees associated with obtaining patents on its new discoveries. Once the patents have been issued, the Company amortizes these costs over the shorter of the legal life of the patent or its estimated economic life using the straight-line method. Amortization expense totaled $86,000 and $62,000 for the years ended December 31, 2019 and 2018, respectively. The Company tests intangible assets with finite lives upon significant changes in the Company’s business environment. The testing resulted in no patent impairment charges during the years ended December 31, 2019 and 2018.