The Elector suggested to Brousson that while at Berlin he should compose a summary account of the condition of the French Protestants, such as should excite the interest and evoke the help of the Protestant rulers and people of the northern States. This was done by Brousson, and the volume was published, entitled "Letters of the Protestants of France who have abandoned all for the cause of the Gospel, to other Protestants; with a particular Letter addressed to Protestant Kings, Electors, Rulers, and Magistrates." The Elector circulated this volume, accompanying it with a letter written in his name, to all the princes of the Continent professing the Augsburg Confession; and it was thus mainly owing to the Elector's intercession that the Huguenots obtained the privilege of establishing congregations in several of the states of Germany, as well as in Sweden and Denmark.
Brousson remained nearly five months at Berlin, after which he departed for Holland to note the progress of the emigration in that country, and there he met a large number of his countrymen. Nearly two hundred and fifty Huguenot ministers had taken refuge in Holland; there were many merchants and manufacturers who had set up their branches of industry in the country; and there were many soldiers who had entered the service of William of Orange. While in Holland, Brousson resided principally with his brother, a banished Huguenot, who had settled at Amsterdam as a merchant.
Having accomplished all that he could for his Huguenot brethren in exile, Brousson returned to Lausanne, where he continued his former labours. He bethought him very much of the Protestants still remaining in France, wandering like sheep without shepherds, deprived of guidance, books, and worship--the prey of ravenous wolves,--and it occurred to him whether the Protestant pastors had done right in leaving their flocks, even though by so doing they had secured the safety of their own lives. Accordingly, in 1686, he wrote and published a "Letter to the Pastors of France at present in Protestant States, concerning the Desolation of their own Churches, and their own Exile."
In this letter he says:--"If, instead of retiring before your persecutors, you had remained in the country; if you had taken refuge in forests and caverns; if you had gone from place to place, risking your lives to instruct and rally the people, until the first shock of the enemy was past; and had you even courageously exposed yourselves to martyrdom--as in fact those have done who have endeavoured to perform your duties in your absence--perhaps the examples of constancy, or zeal, or of piety you had discovered, might have animated your flocks, revived their courage, and arrested the fury of your enemies." He accordingly exhorted the Protestant ministers who had left France to return to their flocks at all hazards.