<sod>Van Leeuwenhoek's work fully captured the attention of the Royal Society, and he began regularly corresponding with the Society regarding his observations. At first he had been reluctant to publicize his findings, regarding himself as a businessman with little scientific, artistic, or writing background, but De Graaf urged him to be more confident in his work.<ref>Dobell, pp. 41–42.</ref> When Van Leeuwenhoek died in 1723, he had written some 190 letters to the Royal Society, detailing his findings in a wide variety of fields, centered on his work in microscopy. He only wrote letters in his own colloquial flavor of Dutch; he never published a proper scientific paper. He strongly preferred to work alone, distrusting the sincerity of those who offered their assistance.<ref>Dobell, pp. 43–44.</ref> The letters were translated into Latin or English by Henry Oldenburg, who had learned Dutch in order to be able to do so.<eod>
<sod>Van Leeuwenhoek's work fully captured the attention of the Royal Society, and he began regularly corresponding with the Society regarding his observations. At first he had been reluctant to publicize his findings, regarding himself as a businessman with little scientific, artistic, or writing background, but De Graaf urged him to be more confident in his work.<ref>Dobell, pp. 41–42.</ref> When Van Leeuwenhoek died in 1723, he had written some 190 letters to the Royal Society, detailing his findings in a wide variety of fields, centered on his work in microscopy. He only wrote letters in his own colloquial flavor of Dutch; he never published a proper scientific paper. He strongly preferred to work alone, distrusting the sincerity of those who offered their assistance.<ref>Dobell, pp. 43–44.</ref> The letters were translated into Latin or English by Henry Oldenburg, who had learned Dutch in order to be able to do so. Despite the initial success of Van Leeuwenhoek's relationship with the Royal Society, this relationship was soon severely strained. In 1676, his credibility was questioned when he sent the Royal Society a copy of his first observations of microscopic single-celled organisms. Previously, the existence of single-celled organisms was entirely unknown. Thus, even with his established reputation with the Royal Society as a reliable observer, his observations of microscopic life were initially met with some skepticism.<ref>{cite journal | url=http://rstb.royalsocietypublishing.org/content/370/1666/20140344 | title=The unseen world: reflections on Leeuwenhoek (1677) Concerning little animals}</ref><eod>