Velnos’ Vegetable Syrup Sold by Isaac Swainson

Isaac Swainson’s famous Velnos’ Vegetable Syrup was a miraculous cure for disease based on vegetables rather than mercury and first appeared in the late 1700s. However, Swainson was not the creator of it. That honor apparently belonged to Jean-Joseph Vergely de Velnos, who then seems to have been aided or succeeded in some way by a Dr. Mercier of Soho.

Velnos’ Vegetable Syrup selling being depicted in cartoon titled “Mercury and his Advocates Defeated, or Vegetable Intrenchment,” by Thomas Rowlandson. Courtesy of Wikipedia.

Swainson was the son of a yeoman named John Swainson and his second wife, Lydia Park. When Swainson was old enough he decided to seek his fortune in London. It was there that he began assisting a woolen draper named Dr. Mercier and it was from him that Swainson purchased the patent medicine called “Velnos’ Vegetable Syrup” for four thousand pounds. Swainson also studied medicine around this time and got his MD in 1785 but was never elected to the Royal College of Physicians.

Swainson first appeared on the scene with his “Velnos’ Vegetable Syrup” in the 1780s. Several others people were already selling the syrup that included John Burrows, Henry Saffory, Edward Baylis, and even Velnos’ widow. In addition, the syrup was sold under variant titles such as “Velno’s, Velnos’, de Velnos’ and De Velnos’s … that may represent typographical preference or … outright piracies of the name.”[1]

Because the syrup supposedly resulted in amazing cures, the exact recipe was kept secret. However, it was said to consist of roots, plants, and flowers from Nigritia. Velnos was alleged to have discovered it during a voyage to Levant (the equivalent of the historical region of Syria today). Nonetheless, some people believed that the active ingredient in Velnos’ syrup had to be Mezereon, a Eurasian shrub with fragrant purplish-red flowers and poisonous red berries. Others theorized it contained Guaiacum, Smilax, or Cinchona because these plants were commonly used at the time to treat or cure venereal disease, and this was one of the supposed benefits of the syrup.  

According to historian Linda Evi Merians:

“In February 1772, a full year before any of his competitor’s treatises, Dr. John Burrows applied for and received a patent for ‘a medicine, called Velno’s Vegetable Syrup.’* He also published his treatise on venereal disease, A Dissertation on the Nature and Effects of a New Vegetable Remedy, which went through multiple editions over the next decade.”[2]

However, even before Burrows applied for a patent, he was advertising Velnos’ Vegetable Syrup. One such advertisement appeared on 18 January of 1772 and began with:

“The following recent Cure will be regarded by the candid and judicious, as a most signal Proof of the Virtues of the Syrup, the reduced State of the Patient considered and the dangerous Situation he was in.”[3]

Velnos’ Vegetable Syrup seller Isaac Swainson

Velnos’ Vegetable Syrup seller Isaac Swainson in 1810. Courtesy of British Museum. Museum Number 1923,0514.173.

Burrows’ advertisements usually contained a testimonial and one continued by providing a story about Edward Martin Esq. of Fenstanton, who had served as the High Sheriff for the counties of Cambridge and Huntingdon. He had allegedly been suffering for years from scurvy, dizziness, and dimness of sight, and to remedy the situation, he took Velnos’ Vegetable Syrup:

“Notwithstanding he had the Advice of the most eminent Physicians, and took a great Variety of Medicines prescribed by them, his Disorder daily increased, and was attended with total Loss of Appetite, and a Lowness of Spirits, insomuch that Life became burthensome to him. In this reduced State, hopeless of any Relief from Medicine, he accidentally met with Dr. Burrows’s Dissertation, and, as the last Effort of Despair, determined to make Trial of the Vegetable Syrup. After taking only seven Bottles, he found his Disorder entirely cured, his Constitution amazingly restored, and he now enjoys a perfect State of health, to the great Astonishment of his Acquaintances.

For the good of Mankind, Mr. Martin is desirous that the above Case should be made public, and will chearfully satisfy any candid Enquirer of the Trust of it.

The Vegetable Syrup confirmed by daily Experiences to be a Specific in all Impurities of the Blood and Juices, (whether Scorbutic or Venereal) is sold in Bottles 10s. 6d. each, at Dr. Burrow’s House opposite the Prince of orange Coffee-House Haymarket; Sold also by Fletcher and Hodson, in Cambridge, (are appointed sole Agents for vending this medicine in the Country), W. Jackson, in Oxford: H. Merrow at Worcester; Pearson and Aris in Birmingham; Mrs. Carnan, at Reading; and Mess. Jopsons, in Coventry. Of whom may be had, A Dissertation on the Nature and Effects, a new Edition, Price 6d.”[4]

Isaac Swainson newspaper advertisements for Velnos’ Vegetable Syrup began popping up sometime later around 1788. One of his first advertisements appeared in January and stated:

“MR. SWAINSON only Proprietor of the genuine Velno’s Syrup, informs the Public, that he has appointed Mr. COLLINS, Bookseller, Salisbury, his wholesale and retail Vender for Salisbury, and the several cities and towns in the circuit of the Salisbury and Winchester Journal, who will supply the Faculty, Trade, and Persons taking a quantity, upon the same terms as it is sold by him in London.

To such as are already acquainted with this medicine, it is presumed the above notice is sufficient, but for the information of those to whom it is yet unknown, they are informed the most extensive practice, and long experience in many of the most inveterate cases, warrant the assurance of its being an UNDOUBTED SPECIFIC CURE in the most deplorable VENEREAL DISEASE, in the LEPROSY, SCURVY, TUMOURS, ULCERS, SCROPHULA, and SCURVY, RHEUMATISM, and PALSY.

The afflicted may with the greatest hope of relief and cure have recourse to this Syrup, even when the most eminent of the Faculty declare their disorder past the reach of Medicine.”[5]

Within a few months of his first advertisement, Swainson began to warn the public about others selling Velnos’ Vegetable Syrup. He cautioned buyers that his version of the vegetable syrup was the only real one. He also noted that he had an affidavit and deed from Mr. and Madame de Velnos and from Dr. Mercier, and that he was the sole “Proprietor and Possessor” of the real Velnos’ Vegetable Syrup:

“Several Gentlemen have kindly apprised me, that pernicious preparations are imposed on the credulous in the country as VELNOS’ VEGETABLE SYRUP. The pretensions of Burrows and Hodson have been amply discussed in town, where there is not a thinking man attentive to the subject, who does not execrate their attempts on my property. I have offered a 1000 guineas, and I repeat the offer, for the slightest proof that De Velnos, or Dr. Mercier, conveyed any knowledge to any person in England but myself. – I am induced to send this warning against their artifices into the country, more by the request of my friends, and humanity to the unfortunate, than by a regard to my own interest. The demand for the genuine syrup in town, and by patients in the country, is nearly as much as I can supply. I am not desirous of extending the country business, unless it be by immediate application to myself; and I have declined numerous solicitations for agents to vend it, because it is difficult to convey without injuring it … Agents are seldom sufficiently attentive in their precautions to preserve it, some have bought quantities of mine, to dispose of cheap and spurious preparations; and few have a sufficient sale to keep it of a proper age. … The sick and diseased will therefore see, that in warning them against the arts of imposition, my object is not to extend my sale in the country, but to prevent irreparable injuries to the unfortunate, and to rescue a medicine of wonderful efficacy and excellence from the discredit of being classed with contemptible or pernicious preparations.”[6]

Like Swainson, Burrows was also advertising that buyers need to watch out for “impostors” so that they were not duped. Perhaps, hoping to outdo Burrows, Swainson also began publishing a complimentary 16-page advertisement, Directions for the Use of Velnos’ Vegetable Syrup. In it he described himself as “sole proprietor of the genuine medicine and successor to Mr. De Velnos.”[7]

Swainson noted that one reason for his advertisement was to provide proper directions for patients taking the syrup, as well as to caution patients about its use. Another reason for Swainson’s free pamphlet was that he hoped to provide information on the “Wars of Regulars and Quacks,” and he also maintained that he could no longer spend four or five hours a day answering letters and messages from the afflicted about the “probability of relief.” In addition, he noted that other pamphlets with additional information about the syrup could be purchased as follows:

  • Letters to a Friend, on the Properties and Effects of Velnos’ Vegetable Syrup for 1s.
  • An Account of the Cures by Velnos’ Vegetable Syrup, in the Venereal Disease for 1s.
  • An Account of Cures by Velnos’ Vegetable Syrup, in disorders classed by the faculty under various denominations, but deriving their origin or malignity from the retention or introduction of morbid matter into the habit; from glandular obstructions or from general impurity of the Lymph, commonly called the Scurvy for a cost of 2s.
Velnos' Vegetable Syrup pamphlet

“An Account of Cures by Velnos’ Vegetable Syrup, in Disorders Deriving Their Origin or Malignity from Scorbutic Impurities” by Isaac Swainson” published in 1794. Author’s Collection.

With all the people selling the syrup and claiming their product was the “legitimate” one, it wasn’t long before there were disputes over who was actually selling the true and original Velnos’ Vegetable Syrup. One dispute happened between Swainson and Baylis and was highlighted in a book about Soho in the late 1800s:

“The receipt was purchased by Mr. Swainson of Dr. Mercier, of Frith Street, and proved a profitable speculation. Nevertheless, he seems to have been involved in a dispute with a Dr. Edward Baylis, who either had, or pretended to have, a copy of the original receipt. Several pamphlets and broadsides were issued by the belligerent parties, between 1775 and 1787, in one of which Dr. Baylis says of his opponent: ‘In consideration of those gentlemen who had taken you from your late servitude as a shopman to a woollen-draper in King Street, Covent Garden, and placed you in your present station, I have long forbore exposing both your situation and your false insinuations respecting the vegetable syrup prepared by me being poisoned with antimony, mercury &c, as you have so termed in your Appendix to your Letters to a Friend, and in your Caution to the Public, &c.”[8]

Isaac Swainson had always dreamed of creating a botanical garden, and, in 1788, his dream came true. It was supposedly financed by Velnos’ Vegetable Syrup as it was claimed he was earning as much as £5,000 a year. With such profits he was easily able to lease the Heath Lane Lodge estate in Twickenham, and under the direction of Daniel Grimwood, a Kensington nurseryman, the garden was laid out. This garden became well-known for its medicinal herbs and “curious plants.” It was also admired not only by nobility and the gentry in the neighborhood but also by many men of science.

Velnos’ Vegetable Syrup - the spot where Swainson's garden grew

South front of Heath Lane Lodge, at Twickenham. Courtesy of British Museum.

Burrows was also selling a great deal of the cure-all syrup. By 1790, he had moved his office to No. 7 Pagrave Place, Strand, near Temple-Bar, and his advertisements for Velnos had changed significantly from the first ones he first placed in 1772. By 1790, he was putting greater emphasis on the syrup’s ability to cure venereal complaints stating that the syrup was “an acknowledged specific in all Venereal, Scorbutic, and Scrophulous Cases.”[9] He also noted that it was the best remedy in the “most desperate Venereal Cases, in all their most obstinate and painful Symptoms, when Salivation and all the ordinary Means had left the unhappy Sufferer without Hopes of Relief.”[10]

In 1792, just as the vegetable syrup was reaching its peak in popularity and sales, Burrows died. “[A]t that point Swainson accused Burrows outright of obtaining his patent under false pretenses, passing off an inferior recipe as the genuine syrup, and essentially stealing the de Velnos name.”[11] Swainson also continued selling Velnos’ Vegetable Syrup and continued advertising that he was the “sole proprietor.” In fact, he did so until his own death on 7 February 1812 (the same day that years earlier in 1770 was the day King Louis XV formally requested the hand of Marie Antoinette for his eldest surviving grandson and heir, the future Louis XVI).

Swainson’s passing was “sincerely lamented by his afflicted relatives, and an extended circle of surviving friends.”[12] Mourners described him as a warm man who cared about “humanity” and consistently exhibited a “benevolence of heart.” Of him they also said that he gave people the benefit of the doubt and that he regularly assumed people were doing their best even when they made errors.

19th-century illustration of Swainsona formosa (Sturt’s Desert Pea) named after Isaac Swainson. Courtesy of Wikipedia.

A week later, on the 14th, Isaac Swainson’s body was accompanied by his family and a few select friends and interred in a family vault at the Twickenham Church. A month or so later a lengthy obituary honoring Swainson was published in the Bury and Norwich Post. It stated that throughout his lifetime he was particularly interested in science and men of science and that he had devoted his life to alleviating the suffering of his “fellow creatures” by using Velnos’ Vegetable Syrup:

“This important duty he discharged with fidelity and diligence, during a period of 30 years; and with a success which has hitherto been unequalled in the annals of medicine. In the performance of his duty, his liberality was eminently conspicuous. His constant language was, that the greatest happiness of his life consisted in being able to mitigate the sufferings of his fellow men; and his actions always kept pace with his profession.”[13]

As to the valuable syrup, the secret recipe was passed on to his nephew, Thomas Canham, Esquire, who had study with Swainson for several years. Canham was supposedly well-prepared “to promote the wonderful effects, and extensive utility of the Medicine, by administering it conformably to the experience of his very respected relative.”[14] Moreover, having observed the syrup’s superior effects upon the sick, Canham hoped to “be as successful as his excellent Predecessor, in impressing on the minds of the afflicted, a proper alarm in the first stages of all debilitating disease; for the corpse may be as soon re-animated, as an Asthma, a Consumption, or a Cancer, cured.”[15]  

*Burrows claimed that he received a patent for the vegetable syrup in 1765.


  • [1] L. E. Merians, The Secret Malady: Venereal Disease in Eighteenth-century Britain and France (Lexington: University Press of Kentucky, 1996), p. 89.
  • [2] L. E. Merians. 1996, p. 90.
  • [3] Oxford Journal, “Velnos’ Vegetable Syrup,” January 18, 1772, p. 4.
  • [4] Ibid.
  • [5] Salisbury and Winchester Journal, “Velno’s Vegetable Syrup,” January 7, 1788, p. 4.
  • [6] Bury and Norwich Post, “Velnos’ Vegetable Syrup,” September 17, 1788, p. 4.
  • [7] I. Swainson, Directions for the Use of Velnos’ Vegetable Syrup (London: James Ridgway, 1790), p. 1.
  • [8] G. Clinch, ed., Soho and Its Associations: Historical, Literary & Artistic (London: Dulau & Co., 1895), p. 105.
  • [9] Norfolk Chronicle, “Velno’s Vegetable Syrup,” January 9, 1790, p. 4.
  • [10] Ibid.
  • [11] L. E. Merians. 1996, p. 91.
  • [12] Bury and Norwich Post, “Mr. Swainson’s Death and Funeral,” March 25, 1812, p. 4.
  • [13] Ibid.
  • [14] Ibid.
  • [15] Ibid.

Oh hi there 👋
It’s nice to meet you.

Sign up to receive awesome content in your inbox, every month.

We don’t spam! Read our privacy policy for more info.

Leave a Comment