Article (magazine)  (2006)  Page(s) 6.  
 
In 1865 he introduced his first rose into commerce - Premier Essai, a hybrid of Rosa roxburghii. Like the famous French breeders Vibert and Descemet, with its breeding he followed the principles of heredity.

Book  (2001)  Page(s) 151.  
 
Quant à l'Allemand Rudolf Geschwind (1829-1910), effectivement grand obtenteur, il travaillera essentiellement en Autriche-Hongrie: mis à part sa première obtention, qu'il appellera, en français, ?Premier Essai' (1866), toutes ses roses n'apparaîtront qu'à l'extrême fin du XIXe siècle.

Book  (1936)  Page(s) 113.  
 
There is a list of these in the Journal des Roses, which I quote, hoping that a few may still be in existence.
Microphylla (hybrids)
.....Premier Essai, flesh white, carmine centre. Geschwind 1566 [sic].

Book  (1936)  Page(s) 242.  
 
Essai, Premier (Microphylla) Geschwind 1866; R. microphylla X Reine de Lombardie; flesh-white, center crimson-red, medium-size, double, growth 7/10, climbing

Magazine  (1908)  Page(s) 133.  
 
Geschwinds first sorts were Premier essai 1866, Dr. Hurta 67, Aurelia Liffa (a macrantah-variety) 86, Forstmeister Heim 86, Fatinitza 86, Erinnerung an Brod 86, Erlkönig 86, Kleiner Postillon 86, Lios Alpha 86, Mercedes 86, Ännchen von Tharau 86, Loreley 87, Meteor 87, Mermaid 87, Schloss Lueg 87, Tartarus, Gilda 87, Virago 87, Esmeralda 88, Erinnerung an meine Mutter 88, Herzblättchen 89, Zigeunerblut 90, Elbfex 90, Anna Scharsach 90, Theano 94, Himmelsauge 95, Erinnerung an Schloss Scharfenstein 1902, Wenzel Geschwind 02, and

Book  (1902)  Page(s) 181.  
 
Rosa microphylla...
6780. Premier Essai (Geschwindt 1866) carné rouge

Book  (1899)  Page(s) 147.  
 
Premier essai, Microphylla, Geschw., 1866, carné centre rouge

Book  (1895)  Page(s) 191.  
 
Rosa microphylla...Le premier essai (Geschwind 1866). A good, vigorous climber and the hardiest of the group. Medium size blooms, the outer petals imbricated, flesh-coloured, white, center carmine-red, fades to fresh pink.

Magazine  (1895)  Page(s) 10.  
 
Premier Essai, Geschwind 1886, flesh-coloured white hybrid.

Magazine  (1895)  Page(s) 27.  
 
Microphylla...Premier Essai, by Geschwind in 1866....